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</head>


<body style="display: inherit; ">
<div class="head">
<p>
</p>
<h1 property="dcterms:title" class="title" id="title">
JSON-LD
Syntax
1.0
</h1>
<h2 property="bibo:subtitle" id="subtitle">
A
Context-based
JSON
Serialization
for
Linking
Data
</h2>
<h2 property="dcterms:issued" datatype="xsd:dateTime" content="2012-05-22T07:54:18+0000" id="unofficial-draft-22-may-2012">
Unofficial
Draft
<del class="diff-old">26
April
</del>
<ins class="diff-chg">22
May
</ins>
2012
</h2>
<dl>
<dt>
Editors:
</dt>
<dd rel="bibo:editor" inlist="">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Manu Sporny" href="http://manu.sporny.org/">
Manu
Sporny
</a>,
<a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">
Digital
Bazaar
</a>
</span>
</dd>
<dd rel="bibo:editor" inlist="">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Gregg Kellogg" href="http://greggkellogg.net/">
Gregg
Kellogg
</a>,
<a rel="foaf:workplaceHomepage" href="http://kellogg-assoc.com/">
Kellogg
Associates
</a>
</span>
</dd>
<dd rel="bibo:editor" inlist="">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">
Markus
Lanthaler
</a>,
<a rel="foaf:workplaceHomepage" href="http://www.tugraz.at/">
Graz
University
of
Technology
</a>
</span>
</dd>
<dt>
Authors:
</dt>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Manu Sporny" href="http://digitalbazaar.com/">
Manu
Sporny
</a>,
<a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">
Digital
Bazaar
</a>
</span>
</dd>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Dave Longley" href="http://digitalbazaar.com/">
Dave
Longley
</a>,
<a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">
Digital
Bazaar
</a>
</span>
</dd>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Gregg Kellogg" href="http://greggkellogg.net/">
Gregg
Kellogg
</a>,
<a rel="foaf:workplaceHomepage" href="http://kellogg-assoc.com/">
Kellogg
Associates
</a>
</span>
</dd>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">
Markus
Lanthaler
</a>,
<a rel="foaf:workplaceHomepage" href="http://www.tugraz.at/">
Graz
University
of
Technology
</a>
</span>
</dd>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Mark Birbeck" href="http://webbackplane.com/">
Mark
Birbeck
</a>,
<a rel="foaf:workplaceHomepage" href="http://webbackplane.com/">
Backplane
Ltd.
</a>
</span>
</dd>
</dl>
<p>
This
document
is
also
available
in
this
non-normative
format:
<a href="diff-20120426.html">
diff
to
previous
version
</a>.
</p>
<p class="copyright">
This
document
is
licensed
under
a
<a class="subfoot" href="http://creativecommons.org/licenses/by/3.0/" rel="license">
Creative
Commons
Attribution
3.0
License
</a>.
</p>
<hr />
</div>
<div id="abstract" class="introductory section" property="dcterms:abstract" datatype="" typeof="bibo:Chapter" resource="#abstract" rel="bibo:chapter">
<h2>
Abstract
</h2>
<p>
JSON
has
proven
to
be
a
highly
useful
object
serialization
and
messaging
format.
In
an
attempt
to
harmonize
the
representation
of
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
in
JSON,
this
specification
outlines
a
common
JSON
representation
format
for
expressing
directed
graphs;
mixing
both
Linked
Data
and
non-Linked
Data
in
a
single
document.
</p>
</div>
<div id="sotd" class="introductory section" typeof="bibo:Chapter" resource="#sotd" rel="bibo:chapter">
<h2>
Status
of
This
Document
</h2>
<p>
This
document
is
merely
a
public
working
draft
of
a
potential
specification.
It
has
no
official
standing
of
any
kind
and
does
not
represent
the
support
or
consensus
of
any
standards
organisation.
</p>
<p>
This
document
is
an
experimental
work
in
progress.
</p>
</div>
<div id="toc" typeof="bibo:Chapter" resource="#toc" rel="bibo:chapter" class="section">
<h2 class="introductory">
Table
of
Contents
</h2>
<ul class="toc">
<li class="tocline">
<a href="#introduction" class="tocxref">
<span class="secno">
1.
</span>
Introduction
</a>
<ul class="toc">
<li class="tocline">
<a href="#how-to-read-this-document" class="tocxref">
<span class="secno">
1.1
</span>
How
to
Read
this
Document
</a>
</li>
<li class="tocline">
<a href="#syntax-tokens-and-keywords" class="tocxref">
<span class="secno">
1.2
</span>
Syntax
Tokens
and
Keywords
</a>
</li>
<li class="tocline">
<a href="#contributing" class="tocxref">
<span class="secno">
1.3
</span>
Contributing
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#design-goals-and-rationale" class="tocxref">
<span class="secno">
2.
</span>
Design
Goals
and
Rationale
</a>
</li>
<li class="tocline">
<a href="#basic-concepts" class="tocxref">
<span class="secno">
3.
</span>
Basic
Concepts
</a>
<ul class="toc">
<li class="tocline">
<a href="#linking-data" class="tocxref">
<span class="secno">
3.1
</span>
Linking
Data
</a>
<ul class="toc">
<li class="tocline">
<a href="#the-context" class="tocxref">
<span class="secno">
3.1.1
</span>
The
Context
</a>
</li>
<li class="tocline">
<a href="#from-json-to-json-ld" class="tocxref">
<span class="secno">
3.1.2
</span>
From
JSON
to
JSON-LD
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#iris" class="tocxref">
<span class="secno">
3.2
</span>
IRIs
</a>
</li>
<li class="tocline">
<a href="#identifying-the-subject" class="tocxref">
<span class="secno">
3.3
</span>
Identifying
the
Subject
</a>
</li>
<li class="tocline">
<a href="#specifying-the-type" class="tocxref">
<span class="secno">
3.4
</span>
Specifying
the
Type
</a>
</li>
<li class="tocline">
<a href="#string-internationalization" class="tocxref">
<span class="secno">
3.5
</span>
String
Internationalization
</a>
</li>
<li class="tocline">
<a href="#sets-and-lists" class="tocxref">
<span class="secno">
3.6
</span>
Sets
and
Lists
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#advanced-concepts" class="tocxref">
<span class="secno">
4.
</span>
Advanced
Concepts
</a>
<ul class="toc">
<li class="tocline">
<a href="#typed-values" class="tocxref">
<span class="secno">
4.1
</span>
Typed
Values
</a>
</li>
<li class="tocline">
<a href="#compact-iris" class="tocxref">
<span class="secno">
4.2
</span>
Compact
IRIs
</a>
</li>
<li class="tocline">
<a href="#external-contexts" class="tocxref">
<span class="secno">
4.3
</span>
External
Contexts
</a>
</li>
<li class="tocline">
<a href="#referencing-contexts-from-json-documents" class="tocxref">
<span class="secno">
4.4
</span>
Referencing
Contexts
from
JSON
Documents
</a>
</li>
<li class="tocline">
<a href="#expanded-term-definition" class="tocxref">
<span class="secno">
4.5
</span>
Expanded
Term
Definition
</a>
</li>
<li class="tocline">
<a href="#type-coercion" class="tocxref">
<span class="secno">
4.6
</span>
Type
Coercion
</a>
</li>
<li class="tocline">
<a href="#iri-expansion-within-a-context" class="tocxref">
<span class="secno">
4.7
</span>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
Expansion
Within
a
Context
</a>
</li>
<li class="tocline">
<a href="#embedding" class="tocxref">
<span class="secno">
4.8
</span>
Embedding
</a>
</li>
<li class="tocline">
<a href="#named-graphs" class="tocxref">
<span class="secno">
4.9
</span>
Named
Graphs
</a>
</li>
<li class="tocline">
<a href="#identifying-unlabeled-nodes" class="tocxref">
<span class="secno">
4.10
</span>
Identifying
Unlabeled
Nodes
</a>
</li>
<li class="tocline">
<a href="#aliasing-keywords" class="tocxref">
<span class="secno">
4.11
</span>
Aliasing
Keywords
</a>
</li>
<li class="tocline">
<a href="#expanded-document-form" class="tocxref">
<span class="secno">
4.12
</span>
<del class="diff-old">Expansion
</del>
<ins class="diff-chg">Expanded
Document
Form
</ins>
</a>
</li>
<li class="tocline">
<a href="#compact-document-form" class="tocxref">
<span class="secno">
4.13
</span>
<del class="diff-old">Compaction
</del>
<ins class="diff-chg">Compact
Document
Form
</ins>
</a>
</li>
<del class="diff-old">4.14
Framing
</del>
</ul>
</li>
<li class="tocline">
<a href="#json-ld-grammar" class="tocxref">
<span class="secno">
<del class="diff-old">4.14.1
</del>
<ins class="diff-chg">A.
</ins>
</span>
<del class="diff-old">Framing
Operators
</del>
<ins class="diff-chg">JSON-LD
Grammar
</ins>
</a>
</li>
<li class="tocline">
<a href="#markup-examples" class="tocxref">
<span class="secno">
<del class="diff-old">A.
</del>
<ins class="diff-chg">B.
</ins>
</span>
Markup
Examples
</a>
<ul class="toc">
<li class="tocline">
<a href="#turtle" class="tocxref">
<span class="secno">
<del class="diff-old">A.1
</del>
<ins class="diff-chg">B.1
</ins>
</span>
Turtle
</a>
<ul class="toc">
<li class="tocline">
<a href="#prefix-definitions" class="tocxref">
<span class="secno">
<del class="diff-old">A.1.1
</del>
<ins class="diff-chg">B.1.1
</ins>
</span>
Prefix
definitions
</a>
</li>
<li class="tocline">
<a href="#embedding-1" class="tocxref">
<span class="secno">
<del class="diff-old">A.1.2
</del>
<ins class="diff-chg">B.1.2
</ins>
</span>
Embedding
</a>
</li>
<li class="tocline">
<a href="#lists" class="tocxref">
<span class="secno">
<del class="diff-old">A.1.3
</del>
<ins class="diff-chg">B.1.3
</ins>
</span>
Lists
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#rdfa" class="tocxref">
<span class="secno">
<del class="diff-old">A.2
</del>
<ins class="diff-chg">B.2
</ins>
</span>
RDFa
</a>
</li>
<li class="tocline">
<a href="#microformats" class="tocxref">
<span class="secno">
<del class="diff-old">A.3
</del>
<ins class="diff-chg">B.3
</ins>
</span>
Microformats
</a>
</li>
<li class="tocline">
<a href="#microdata" class="tocxref">
<span class="secno">
<del class="diff-old">A.4
</del>
<ins class="diff-chg">B.4
</ins>
</span>
Microdata
</a>
</li>
</ul>
</li>
<li class="tocline">
<del class="diff-old">B.
Linked
Data
C.
Mashing
Up
Vocabularies
</del>
<a href="#iana-considerations" class="tocxref">
<span class="secno">
<del class="diff-old">D.
</del>
<ins class="diff-chg">C.
</ins>
</span>
IANA
Considerations
</a>
</li>
<li class="tocline">
<a href="#acknowledgements" class="tocxref">
<span class="secno">
<del class="diff-old">E.
</del>
<ins class="diff-chg">D.
</ins>
</span>
Acknowledgements
</a>
</li>
<li class="tocline">
<a href="#references" class="tocxref">
<span class="secno">
<del class="diff-old">F.
</del>
<ins class="diff-chg">E.
</ins>
</span>
References
</a>
<ul class="toc">
<li class="tocline">
<a href="#normative-references" class="tocxref">
<span class="secno">
<del class="diff-old">F.1
</del>
<ins class="diff-chg">E.1
</ins>
</span>
Normative
references
</a>
</li>
<li class="tocline">
<a href="#informative-references" class="tocxref">
<span class="secno">
<del class="diff-old">F.2
</del>
<ins class="diff-chg">E.2
</ins>
</span>
Informative
references
</a>
</li>
</ul>
</li>
</ul>
</div>
<div class="informative section" id="introduction" typeof="bibo:Chapter" resource="#introduction" rel="bibo:chapter">
<h2>
<span class="secno">
1.
</span>
Introduction
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
JSON,
as
specified
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC4627">
RFC4627
</a>
</cite>
],
is
a
simple
language
for
representing
data
on
the
Web.
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
is
a
technique
for
creating
a
<del class="diff-old">graph
</del>
<ins class="diff-chg">network
</ins>
of
<del class="diff-old">interlinked
</del>
<ins class="diff-chg">inter-connected
</ins>
data
across
different
<ins class="diff-new">Web
</ins>
documents
<del class="diff-old">or
</del>
<ins class="diff-chg">and
</ins>
Web
sites.
<del class="diff-old">Data
entities
are
described
</del>
<ins class="diff-chg">A
</ins><em><ins class="diff-chg">
thing
</ins></em><ins class="diff-chg">
in
this
data
network
is
typically
identified
</ins>
using
<ins class="diff-new">an
</ins>
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<del class="diff-old">s,
</del>
<ins class="diff-chg">(Internationalized
Resource
Identifier),
</ins>
which
<del class="diff-old">are
</del>
<ins class="diff-chg">is
</ins>
typically
<del class="diff-old">dereferencable
</del>
<ins class="diff-chg">dereference-able,
</ins>
and
thus
may
be
used
to
find
more
information
about
<del class="diff-old">an
entity,
creating
</del>
<ins class="diff-chg">the
</ins><em><ins class="diff-chg">
thing
</ins></em>.<ins class="diff-chg">
The
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a><ins class="diff-chg">
allows
</ins>
a
<del class="diff-old">&quot;Web
of
Knowledge&quot;.
JSON-LD
is
intended
</del>
<ins class="diff-chg">software
program
</ins>
to
<del class="diff-old">be
a
simple
publishing
method
for
expressing
not
only
Linked
Data
</del>
<ins class="diff-chg">start
at
one
</ins><em><ins class="diff-chg">
thing
</ins></em><ins class="diff-chg">
and
follow
links
to
other
</ins><em><ins class="diff-chg">
things
</ins></em>
in
<del class="diff-old">JSON,
but
also
for
adding
semantics
</del>
<ins class="diff-chg">order
</ins>
to
<del class="diff-old">existing
JSON.
</del>
<ins class="diff-chg">learn
more
about
all
of
the
things
described
on
the
Web.
</ins>
</p>
<p>
JSON-LD
is
designed
as
a
lightweight
syntax
that
can
be
used
to
express
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
It
is
primarily
intended
to
be
a
way
to
use
Linked
Data
in
Javascript
and
other
Web-based
programming
environments.
It
is
also
useful
when
building
<del class="diff-old">interoperable
</del>
<ins class="diff-chg">inter-operable
</ins>
Web
services
and
when
storing
Linked
Data
in
JSON-based
document
storage
engines.
It
is
practical
and
designed
to
be
as
simple
as
possible,
utilizing
the
large
number
of
JSON
parsers
and
libraries
available
today.
</p>
<p>
The
syntax
does
not
necessarily
require
applications
to
change
their
JSON,
but
allows
one
to
easily
add
meaning
by
simply
adding
or
referencing
a
context.
The
syntax
is
designed
to
not
disturb
already
deployed
systems
running
on
JSON,
but
provide
a
smooth
upgrade
path
from
JSON
to
<del class="diff-old">JSON-LD
with
added
semantics.
</del>
<ins class="diff-chg">JSON-LD.
</ins>
Finally,
the
format
is
intended
to
be
easy
to
parse,
efficient
to
generate,
and
only
requires
a
very
small
memory
footprint
in
order
to
operate.
</p>
<div id="how-to-read-this-document" typeof="bibo:Chapter" resource="#how-to-read-this-document" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
1.1
</span>
How
to
Read
this
Document
</h3>
<p>
This
document
is
a
detailed
specification
for
a
serialization
of
Linked
Data
in
JSON.
The
document
is
primarily
intended
for
the
following
audiences:
</p>
<ul>
<li>
Software
developers
that
want
to
encode
Linked
Data
in
a
way
that
is
cross-language
compatible
via
JSON.
</li>
<li>
Software
developers
that
want
to
understand
the
design
decisions
and
language
syntax
for
JSON-LD.
</li>
<li>
Software
developers
that
want
to
implement
processors
and
APIs
for
JSON-LD.
</li>
</ul>
<p>
This
specification
does
not
describe
the
programming
interfaces
for
the
JSON-LD
Syntax.
The
specification
that
describes
the
programming
interfaces
for
JSON-LD
documents
is
the
JSON-LD
Application
Programming
Interface
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
].
</p>
<p>
To
understand
the
basics
in
this
specification
you
must
first
be
familiar
with
JSON,
which
is
detailed
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC4627">
RFC4627
</a>
</cite>
].
<del class="diff-old">To
understand
the
API
and
how
it
is
intended
to
operate
in
a
programming
environment,
it
is
useful
to
have
working
knowledge
of
the
JavaScript
programming
language
[
ECMA-262
]
and
WebIDL
[
WEBIDL
].
</del>
</p>
<p>
JSON
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC4627">
RFC4627
</a>
</cite>
]
defines
several
terms
which
are
used
throughout
this
document:
</p>
<dl>
<dt>
<dfn title="json_object" id="dfn-json_object">
JSON
object
</dfn>
</dt>
<dd>
An
object
structure
is
represented
as
a
pair
of
curly
brackets
surrounding
zero
or
more
<del class="diff-old">name/value
pairs
(or
members).
</del>
<ins class="diff-chg">name-value
pairs.
</ins>
A
name
is
a
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>.
A
single
colon
comes
after
each
name,
separating
the
name
from
the
value.
A
single
comma
separates
a
value
from
a
following
name.
The
names
within
an
object
<em class="rfc2119" title="should">
should
</em>
be
unique.
</dd>
<dt>
<dfn title="array" id="dfn-array">
array
</dfn>
</dt>
<dd>
<del class="diff-old">An
</del>
<ins class="diff-chg">In
JSON,
an
</ins>
array
is
an
<em>
ordered
</em>
collection
of
values.
An
array
<del class="diff-old">structure
</del>
is
represented
as
square
brackets
surrounding
zero
or
more
values
<del class="diff-old">(or
elements).
Elements
</del>
<ins class="diff-chg">that
</ins>
are
separated
by
commas.
<del class="diff-old">Within
JSON-LD,
</del>
<ins class="diff-chg">While
JSON-LD
uses
the
same
</ins>
array
<ins class="diff-new">representation
as
JSON,
the
collection
is
</ins><em><ins class="diff-new">
unordered
</ins></em><ins class="diff-new">
by
default.
While
</ins>
order
is
<del class="diff-old">not
</del>
preserved
<del class="diff-old">by
default,
</del>
<ins class="diff-chg">in
regular
JSON
arrays,
it
is
not
in
regular
JSON-LD
arrays
</ins>
unless
specific
markup
is
provided
(see
<a href="#sets-and-lists">
Sets
and
Lists
</a>
).
<del class="diff-old">This
is
because
the
basic
data
model
of
JSON-LD
is
a
linked
data
graph
,
which
is
inherently
unordered.
</del>
</dd>
<dt>
<dfn title="string" id="dfn-string">
string
</dfn>
</dt>
<dd>
A
string
is
a
sequence
of
zero
or
more
Unicode
<ins class="diff-new">(UTF-8)
</ins>
characters,
wrapped
in
double
quotes,
using
backslash
<del class="diff-old">escapes.
</del>
<ins class="diff-chg">escapes
(if
necessary).
</ins>
A
character
is
represented
as
a
single
character
string.
</dd>
<dt>
<dfn title="number" id="dfn-number">
number
</dfn>
</dt>
<dd>
A
number
is
is
similar
to
that
used
in
most
programming
languages,
except
that
the
octal
and
hexadecimal
formats
are
not
used
and
that
leading
zeros
are
not
allowed.
</dd>
<dt>
<dfn title="true" id="dfn-true">
true
</dfn>
and
<dfn title="false" id="dfn-false">
false
</dfn>
</dt>
<dd>
Values
that
are
used
to
express
one
of
two
possible
boolean
states.
</dd>
<dt>
<dfn title="null" id="dfn-null">
null
</dfn>
</dt>
<dd>
Unless
otherwise
specified,
a
JSON-LD
processor
<em class="rfc2119" title="must">
must
</em>
act
as
if
a
key-value
pair
in
the
body
of
a
JSON-LD
document
was
never
declared
when
the
value
equals
<em>
null
</em>.
If
<code>
@value
</code>,
<code>
@list
</code>,
or
<code>
@set
</code>
is
set
to
<em>
null
</em>
in
expanded
form,
then
the
entire
JSON
object
is
ignored.
If
<code>
@context
</code>
is
set
to
<em>
null
</em>,
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
is
reset
and
when
used
within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>,
it
removes
any
definition
associated
with
the
key,
unless
otherwise
specified.
</dd>
<dt>
<dfn title="subject_definition" id="dfn-subject_definition">
subject
definition
</dfn>
</dt>
<dd>
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
used
to
represent
a
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
and
one
or
more
properties
of
that
subject.
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
is
a
subject
definition
if
it
does
not
contain
they
keys
<code>
@value
</code>,
<code>
@list
</code>
or
<code>
@set
</code>
and
it
has
one
or
more
keys
other
than
<code>
@id
</code>.
</dd>
<dt>
<dfn title="subject_reference" id="dfn-subject_reference">
subject
reference
</dfn>
</dt>
<dd>
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
used
to
reference
a
subject
having
only
the
<code>
@id
</code>
key.
</dd>
</dl>
<p>
</p>
</div>
<div id="syntax-tokens-and-keywords" typeof="bibo:Chapter" resource="#syntax-tokens-and-keywords" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
1.2
</span>
Syntax
Tokens
and
Keywords
</h3>
<p>
JSON-LD
specifies
a
number
of
syntax
tokens
and
<dfn title="keyword" id="dfn-keyword">
keywords
</dfn>
that
are
<del class="diff-old">using
in
all
algorithms
described
in
this
section:
</del>
<ins class="diff-chg">a
core
part
of
the
language:
</ins>
</p>
<dl>
<dt>
<code>
@context
</code>
</dt>
<dd>
Used
to
define
the
short-hand
names
that
are
used
throughout
a
JSON-LD
document.
These
short-hand
names
are
called
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
and
help
developers
to
express
specific
identifiers
in
a
compact
manner.
The
<code>
@context
</code>
keyword
is
described
in
detail
in
the
section
titled
<a href="#the-context">
The
Context
</a>.
</dd>
<dt>
<code>
@graph
</code>
</dt>
<dd>
Used
to
explicitly
express
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>.
</dd>
<dt>
<code>
@id
</code>
</dt>
<dd>
Used
to
uniquely
identify
<em>
things
</em>
that
are
being
described
in
the
document.
This
keyword
is
described
in
the
section
titled
<a href="#identifying-the-subject">
Identifying
the
Subject
</a>.
</dd>
<dt>
<code>
@value
</code>
</dt>
<dd>
Used
to
specify
the
data
that
is
associated
with
a
particular
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
in
the
graph.
This
keyword
is
described
in
the
sections
titled
<a href="#string-internationalization">
String
Internationalization
</a>
and
<a href="#typed-values">
Typed
Values
</a>.
</dd>
<dt>
<code>
@language
</code>
</dt>
<dd>
Used
to
specify
the
native
language
for
a
particular
value
or
the
default
language
of
a
JSON-LD
document.
This
keyword
is
described
in
the
section
titled
<a href="#string-internationalization">
String
Internationalization
</a>.
</dd>
<dt>
<code>
@type
</code>
</dt>
<dd>
Used
to
set
the
data
type
of
a
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
or
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>.
This
keyword
is
described
in
the
section
titled
<a href="#typed-values">
Typed
Values
</a>.
</dd>
<dt>
<code>
@container
</code>
</dt>
<dd>
Used
to
set
the
container
of
a
particular
value.
This
keyword
is
described
in
the
section
titled
<a href="#sets-and-lists">
Sets
and
Lists
</a>.
</dd>
<dt>
<code>
@list
</code>
</dt>
<dd>
Used
to
express
an
ordered
set
of
data.
This
keyword
is
described
in
the
section
titled
<a href="#sets-and-lists">
Sets
and
Lists
</a>.
</dd>
<dt>
<code>
@set
</code>
</dt>
<dd>
Used
to
express
an
unordered
set
of
data.
This
keyword
is
described
in
the
section
titled
<a href="#sets-and-lists">
Sets
and
Lists
</a>.
</dd>
<dt>
<code>:
</code>
</dt>
<dd>
The
separator
for
JSON
keys
and
values
that
use
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>.
</dd>
</dl>
<p>
For
the
avoidance
of
doubt,
all
keys,
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>,
and
values
in
JSON-LD
are
case-sensitive.
</p>
</div>
<div id="contributing" typeof="bibo:Chapter" resource="#contributing" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
1.3
</span>
Contributing
</h3>
<p>
There
are
a
number
of
ways
that
one
may
participate
in
the
development
of
this
specification:
</p>
<ul>
<li>
Technical
discussion
typically
occurs
on
the
public
mailing
list:
<a href="http://lists.w3.org/Archives/Public/public-linked-json/">
public-linked-json@w3.org
</a>
</li>
<li>
<a href="http://json-ld.org/minutes/">
Public
teleconferences
</a>
are
held
every
week
on
Tuesdays
at
1500
UTC.
</li>
<li>
Specification
bugs
and
issues
should
be
reported
<del class="diff-old">in
</del>
<ins class="diff-chg">using
</ins>
the
<a href="https://github.com/json-ld/json-ld.org/issues">
issue
tracker
</a>.
</li>
<li>
<a href="https://github.com/json-ld/json-ld.org/tree/main/spec">
Source
code
</a>
for
the
specification
can
be
found
on
Github.
</li>
<li>
The
<a href="http://webchat.freenode.net/?channels=json-ld">
#json-ld
</a>
IRC
channel
is
available
for
real-time
discussion
on
irc.freenode.net.
</li>
</ul>
</div>
</div>
<div class="informative section" id="design-goals-and-rationale" typeof="bibo:Chapter" resource="#design-goals-and-rationale" rel="bibo:chapter">
<h2>
<span class="secno">
2.
</span>
Design
Goals
and
Rationale
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
A
number
of
design
<del class="diff-old">considerations
</del>
<ins class="diff-chg">goals
</ins>
were
<del class="diff-old">explored
during
</del>
<ins class="diff-chg">established
before
</ins>
the
creation
of
this
markup
language:
</p>
<dl>
<dt>
Simplicity
</dt>
<dd>
<ins class="diff-new">No
extra
processors
or
software
libraries
should
be
necessary
to
use
JSON-LD
in
its
most
basic
form.
The
language
will
provide
developers
with
a
very
easy
learning
curve.
</ins>
Developers
need
only
know
JSON
and
two
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>
(
<code>
@context
</code>
and
<code>
@id
</code>
)
to
use
the
basic
functionality
in
JSON-LD.
<del class="diff-old">No
extra
processors
or
software
libraries
are
necessary
to
use
JSON-LD
in
its
most
basic
form.
The
language
attempts
to
ensure
that
developers
have
an
easy
learning
curve.
</del>
</dd>
<dt>
Compatibility
</dt>
<dd>
The
JSON-LD
markup
must
be
100%
compatible
with
JSON.
This
ensures
that
all
of
the
standard
JSON
libraries
work
seamlessly
with
JSON-LD
documents.
</dd>
<dt>
Expressiveness
</dt>
<dd>
The
syntax
must
be
able
to
express
directed
graphs,
which
have
been
proven
to
be
able
to
express
almost
every
real
world
data
model.
</dd>
<dt>
Terseness
</dt>
<dd>
The
JSON-LD
syntax
must
be
very
terse
and
human
readable,
requiring
as
little
effort
as
possible
from
the
developer.
</dd>
<dt>
Zero
Edits,
most
of
the
time
</dt>
<dd>
JSON-LD
<del class="diff-old">provides
</del>
<ins class="diff-chg">must
provide
</ins>
a
<a href="#referencing-contexts-from-json-documents">
mechanism
</a>
that
allows
developers
to
specify
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
in
a
way
that
is
out-of-band.
This
allows
organizations
that
have
already
deployed
large
JSON-based
infrastructure
to
add
meaning
to
their
JSON
documents
in
a
way
that
is
not
disruptive
to
their
day-to-day
operations
and
is
transparent
to
their
current
customers.
At
times,
mapping
JSON
to
a
graph
representation
can
become
difficult.
In
these
instances,
rather
than
having
JSON-LD
support
<ins class="diff-new">an
</ins>
esoteric
<del class="diff-old">markup,
</del>
<ins class="diff-chg">use
case,
</ins>
we
chose
not
to
support
the
use
case
and
support
a
simplified
syntax
instead.
So,
while
Zero
Edits
is
a
goal,
it
is
not
always
possible
without
adding
great
complexity
to
the
language.
</dd>
<dt>
One-pass
Processing
</dt>
<dd>
JSON-LD
supports
one-pass
processing,
which
results
in
a
very
small
memory
footprint
when
processing
documents.
For
example,
to
expand
a
JSON-LD
document
from
a
compacted
form,
only
one
pass
is
required
over
the
data.
</dd>
</dl>
</div>
<div id="basic-concepts" typeof="bibo:Chapter" resource="#basic-concepts" rel="bibo:chapter" class="section">
<h2>
<span class="secno">
3.
</span>
Basic
Concepts
</h2>
<p>
JSON-LD
is
designed
to
ensure
that
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
concepts
can
be
marked
up
in
a
way
that
is
simple
to
understand
and
create
by
Web
authors.
In
many
cases,
regular
JSON
markup
can
become
Linked
Data
with
the
simple
addition
of
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
As
more
JSON-LD
features
are
used,
more
semantics
are
added
to
the
JSON
markup.
</p>
<div id="linking-data" typeof="bibo:Chapter" resource="#linking-data" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
3.1
</span>
Linking
Data
</h3>
<p>
<del class="diff-old">An
Internationalized
Resource
Identifier
(
</del>
<ins class="diff-chg">The
following
definition
for
</ins><a class="tref internalDFN" title="linked_data" href="#dfn-linked_data"><ins class="diff-chg">
Linked
Data
</ins></a><ins class="diff-chg">
is
the
one
that
will
be
used
for
this
specification.
</ins></p><ol><li><dfn title="linked_data" id="dfn-linked_data"><ins class="diff-chg">
Linked
Data
</ins></dfn><ins class="diff-chg">
is
a
set
of
documents,
each
containing
a
representation
of
a
linked
data
graph.
</ins></li><li><ins class="diff-chg">
A
</ins><dfn title="linked_data_graph" id="dfn-linked_data_graph"><ins class="diff-chg">
linked
data
graph
</ins></dfn><ins class="diff-chg">
is
an
unordered
labeled
directed
graph,
where
nodes
are
</ins><a class="tref internalDFN" title="subject" href="#dfn-subject"><ins class="diff-chg">
subject
</ins></a><ins class="diff-chg">
s
or
</ins><a class="tref internalDFN" title="object" href="#dfn-object"><ins class="diff-chg">
object
</ins></a><ins class="diff-chg">
s,
and
edges
are
properties.
</ins></li><li><ins class="diff-chg">
A
</ins><dfn title="subject" id="dfn-subject"><ins class="diff-chg">
subject
</ins></dfn><ins class="diff-chg">
is
any
node
in
a
</ins><a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph"><ins class="diff-chg">
linked
data
graph
</ins></a><ins class="diff-chg">
with
at
least
one
outgoing
edge.
</ins></li><li><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="subject" href="#dfn-subject"><ins class="diff-chg">
subject
</ins></a><em class="rfc2119" title="should"><ins class="diff-chg">
should
</ins></em><ins class="diff-chg">
be
labeled
with
an
</ins>
<dfn title="iri" id="dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
<del class="diff-old">),
</del>
<ins class="diff-chg">(an
Internationalized
Resource
Identifier
</ins>
as
described
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC3987">
RFC3987
</a>
</cite>
<del class="diff-old">],
</del>
<ins class="diff-chg">]).
</ins></li><li><ins class="diff-chg">
An
</ins><dfn title="object" id="dfn-object"><ins class="diff-chg">
object
</ins></dfn>
is
a
<del class="diff-old">mechanism
for
representing
unique
identifiers
on
</del>
<ins class="diff-chg">node
in
a
</ins><a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph"><ins class="diff-chg">
linked
data
graph
</ins></a><ins class="diff-chg">
with
at
least
one
incoming
edge.
</ins></li><li><ins class="diff-chg">
An
</ins><a class="tref internalDFN" title="object" href="#dfn-object"><ins class="diff-chg">
object
</ins></a><em class="rfc2119" title="may"><ins class="diff-chg">
may
</ins></em><ins class="diff-chg">
be
labeled
with
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a>.</li><li><ins class="diff-chg">
A
node
</ins><em class="rfc2119" title="may"><ins class="diff-chg">
may
</ins></em><ins class="diff-chg">
be
a
</ins><a class="tref internalDFN" title="subject" href="#dfn-subject"><ins class="diff-chg">
subject
</ins></a><ins class="diff-chg">
and
</ins><a class="tref internalDFN" title="object" href="#dfn-object"><ins class="diff-chg">
object
</ins></a><ins class="diff-chg">
at
</ins>
the
<del class="diff-old">Web.
In
Linked
Data
,
</del>
<ins class="diff-chg">same
time.
</ins></li><li><ins class="diff-chg">
A
</ins><dfn title="property" id="dfn-property"><ins class="diff-chg">
property
</ins></dfn><ins class="diff-chg">
is
</ins>
an
<ins class="diff-new">edge
of
the
</ins><a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph"><ins class="diff-new">
linked
data
graph
</ins></a>.</li><li><ins class="diff-new">
A
</ins><a class="tref internalDFN" title="property" href="#dfn-property"><ins class="diff-new">
property
</ins></a><em class="rfc2119" title="should"><ins class="diff-new">
should
</ins></em><ins class="diff-new">
be
labeled
with
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>.</li><li><ins class="diff-new">
An
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<ins class="diff-new">that
</ins>
is
<del class="diff-old">commonly
used
for
expressing
</del>
a
<ins class="diff-new">label
in
a
</ins><a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph"><ins class="diff-new">
linked
data
graph
</ins></a><em class="rfc2119" title="should"><ins class="diff-new">
should
</ins></em><ins class="diff-new">
be
dereferencable
to
a
</ins><a class="tref internalDFN" title="linked_data" href="#dfn-linked_data"><ins class="diff-new">
Linked
Data
</ins></a><ins class="diff-new">
document
describing
the
labeled
</ins>
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>,
<del class="diff-old">a
property
</del>
<a class="tref internalDFN" title="object" href="#dfn-object">
<ins class="diff-chg">object
</ins>
</a>
or
<a class="tref internalDFN" title="property" href="#dfn-property">
<ins class="diff-new">property
</ins></a>.</li><li><ins class="diff-new">
A
</ins><dfn title="value" id="dfn-value"><ins class="diff-new">
value
</ins></dfn><ins class="diff-new">
is
</ins>
an
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
<ins class="diff-new">with
a
label
that
is
not
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a></li></ol><p class="issue"><ins class="diff-new">
An
illustration
of
a
linked
data
graph
would
probably
help
here.
</ins></p><p><ins class="diff-new">
Note
that
the
definition
for
</ins><a class="tref internalDFN" title="linked_data" href="#dfn-linked_data"><ins class="diff-new">
Linked
Data
</ins></a><ins class="diff-new">
above
is
silent
on
the
topic
of
unlabeled
nodes.
Unlabeled
nodes
are
not
considered
</ins><a class="tref internalDFN" title="linked_data" href="#dfn-linked_data"><ins class="diff-new">
Linked
Data
</ins>
</a>.
<ins class="diff-new">However,
this
specification
allows
for
the
expression
of
unlabled
nodes,
as
most
graph-based
data
sets
on
the
Web
contain
a
number
of
associated
nodes
that
are
not
named
and
thus
are
not
directly
de-referenceable.
</ins>
</p>
<p>
JSON-LD
defines
a
mechanism
to
map
JSON
terms,
i.e.,
keys
and
values,
to
IRIs.
This
does
not
mean
that
JSON-LD
requires
every
key
or
value
to
be
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
but
rather
ensures
that
keys
and
values
can
be
mapped
to
IRIs
if
the
developer
desires
to
transform
their
data
into
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
There
are
a
few
techniques
that
can
ensure
that
developers
will
generate
good
Linked
Data
for
the
Web.
JSON-LD
formalizes
those
techniques.
</p>
<p>
We
will
be
using
the
following
JSON
markup
as
the
example
for
the
rest
of
this
section:
</p>
<del class="diff-old">{
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<div id="the-context" typeof="bibo:Chapter" resource="#the-context" rel="bibo:chapter" class="section">
<h4>
<span class="secno">
3.1.1
</span>
The
Context
</h4>
<p>
In
JSON-LD,
a
<dfn title="context" id="dfn-context">
context
</dfn>
is
used
to
map
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s,
i.e.,
properties
with
associated
values
in
an
JSON
document,
to
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s.
A
<dfn title="term" id="dfn-term">
term
</dfn>
is
a
short
word
that
expands
to
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
<em class="rfc2119" title="may">
may
</em>
be
defined
as
any
valid
JSON
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
other
than
a
JSON-LD
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>.
To
avoid
forward-compatibility
issues,
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
starting
with
an
<code>
@
</code>
character
<em class="rfc2119" title="should not">
should
not
</em>
be
used
as
they
might
be
used
as
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>
in
future
versions
of
JSON-LD.
<ins class="diff-new">Furthermore,
the
use
of
empty
terms
(
</ins><code><ins class="diff-new">
&quot;&quot;
</ins></code><ins class="diff-new">
)
is
discouraged
as
not
all
programming
languages
are
able
to
handle
empty
property
names.
</ins>
</p>
<p>
The
Web
uses
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>
for
unambiguous
identification.
The
idea
is
that
these
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
mean
something
that
may
be
of
use
to
other
developers
and
that
it
is
useful
to
give
them
an
unambiguous
identifier.
That
is,
it
is
useful
for
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
to
expand
to
IRIs
so
that
developers
don't
accidentally
step
on
each
other's
<dfn title="vocabulary" id="dfn-vocabulary">
vocabulary
</dfn>
terms.
Furthermore,
developers,
and
machines,
are
able
to
use
this
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
(by
plugging
it
directly
into
a
web
browser,
for
instance)
to
go
to
the
term
and
get
a
definition
of
what
the
term
means.
<del class="diff-old">Much
like
</del>
<ins class="diff-chg">This
mechanism
is
analogousto
the
way
</ins>
we
can
use
<a href="http://wordnet.princeton.edu/">
WordNet
</a>
today
to
see
the
definition
of
words
in
the
English
language.
Developers
and
machines
need
the
same
sort
of
definition
of
terms.
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>
provide
a
way
to
ensure
that
these
terms
are
unambiguous.
For
example,
the
term
<code>
name
</code>
may
map
directly
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/name
</code>.
This
allows
JSON-LD
documents
to
be
constructed
using
the
common
JSON
practice
of
simple
name/value
pairs
while
ensuring
that
the
data
is
useful
outside
of
the
page,
API
or
database
in
which
it
resides.
The
value
of
a
term
mapping
<em class="rfc2119" title="must">
must
</em>
be
either;
1)
a
simple
string
with
the
lexical
form
of
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
2)
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
or
3)
an
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
containing
an
<code>
@id
</code>,
<code>
@type
</code>,
<code>
@language
</code>,
or
<code>
@container
</code>
keyword
(all
other
keywords
are
ignored
by
a
JSON-LD
processor).
</p>
<p>
These
Linked
Data
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
are
typically
collected
in
a
context
document
that
would
look
something
like
this:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  }
</ins>
}
</pre>
<p>
Assuming
that
this
context
document
can
be
retrieved
at
<code>
http://json-ld.org/contexts/person
</code>,
it
can
be
referenced
from
a
JSON-LD
document
by
adding
a
single
line.
The
JSON
markup
shown
in
the
previous
section
could
be
changed
as
follows:
</p>
<del class="diff-old">{
  
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;: &quot;http://json-ld.org/contexts/person&quot;,</span>
<ins class="diff-chg">  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<p>
The
additions
above
transform
the
previous
JSON
document
into
a
JSON
document
with
added
semantics
because
the
<code>
@context
</code>
specifies
how
the
<strong>
name
</strong>,
<strong>
homepage
</strong>,
and
<strong>
depiction
</strong>
terms
map
to
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>.
Mapping
those
keys
to
IRIs
gives
the
data
global
context.
If
two
developers
use
the
same
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
to
describe
a
property,
they
are
more
than
likely
expressing
the
same
concept.
This
allows
both
developers
to
re-use
each
others
data
without
having
to
agree
to
how
their
data
will
interoperate
on
a
site-by-site
basis.
Contexts
may
also
contain
type
information
for
certain
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
as
well
as
other
processing
instructions
for
the
JSON-LD
processor.
</p>
<p>
Contexts
<em class="rfc2119" title="may">
may
</em>
be
specified
in-line.
This
ensures
that
JSON-LD
documents
can
be
processed
when
a
JSON-LD
processor
does
not
have
access
to
the
Web.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  },</span>
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<p>
Contexts
<em class="rfc2119" title="may">
may
</em>
be
used
at
any
time
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
is
defined.
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
<em class="rfc2119" title="may">
may
</em>
specify
multiple
contexts,
using
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>,
which
is
processed
in
order.
This
is
useful
when
an
author
would
like
to
use
an
existing
context
and
add
application-specific
terms
to
the
existing
context.
Duplicate
context
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
<em class="rfc2119" title="must">
must
</em>
be
overridden
using
a
last-defined-overrides
mechanism.
</p>
<p class="note">
If
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
is
re-defined
within
a
context,
all
previous
rules
associated
with
the
previous
definition
are
removed.
A
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
defined
in
a
previous
context
<em class="rfc2119" title="must">
must
</em>
be
removed,
if
it
is
re-defined
to
<code>
null
</code>.
</p>
<p>
The
set
of
contexts
defined
within
a
specific
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
are
referred
to
as
<dfn title="local_context" id="dfn-local_context">
local
context
</dfn>
s.
Setting
the
context
to
<code>
null
</code>
effectively
sets
the
<a class="tref internalDFN" title="local_context" href="#dfn-local_context">
local
context
</a>
to
<del class="diff-old">it's
</del>
<ins class="diff-chg">its
</ins>
initial
state.
The
<dfn title="active_context" id="dfn-active_context">
active
context
</dfn>
refers
to
the
accumulation
of
<a class="tref internalDFN" title="local_context" href="#dfn-local_context">
local
context
</a>
s
that
are
in
scope
at
a
specific
point
within
the
document.
The
following
example
specifies
an
external
context
and
then
layers
a
local
context
on
top
of
the
external
context:
</p>
<del class="diff-old">{
  &quot;@context&quot;: [
    &quot;http://json-ld.org/contexts/person&quot;,
    {
      &quot;pic&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;
    }
  ],
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;: [
<ins class="diff-chg">    &quot;http://json-ld.org/contexts/person&quot;,
    {
      &quot;pic&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;
    }
  ],</span>
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
</ins>  <span class="diff">&quot;pic&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;</span>
}
</pre>
<p class="note">
To
ensure
the
best
possible
performance,
it
is
a
best
practice
to
put
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition
at
the
top
of
the
JSON-LD
document.
If
it
isn't
listed
first,
processors
have
to
save
each
key-value
pair
until
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
is
processed.
This
creates
a
memory
and
complexity
burden
for
one-pass
processors.
</p>
</div>
<div id="from-json-to-json-ld" typeof="bibo:Chapter" resource="#from-json-to-json-ld" rel="bibo:chapter" class="section">
<h4>
<span class="secno">
3.1.2
</span>
From
JSON
to
JSON-LD
</h4>
<p>
If
a
set
of
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
such
as,
<strong>
name
</strong>,
<strong>
homepage
</strong>,
and
<strong>
depiction
</strong>,
are
defined
in
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>,
and
that
context
is
used
to
resolve
the
names
in
JSON
objects,
machines
are
able
to
automatically
expand
the
terms
to
something
meaningful
and
unambiguous,
like
this:
</p>
<del class="diff-old">{
  &quot;&quot;: &quot;Manu Sporny&quot;,
  &quot;&quot;: &quot;http://manu.sporny.org&quot;
  &quot;&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;<span class="diff">http://xmlns.com/foaf/0.1/name</span>&quot;: &quot;Manu Sporny&quot;,
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>&quot;: &quot;http://manu.sporny.org&quot;
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/depiction</span>&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<p>
Doing
this
allows
JSON
to
be
unambiguously
machine-readable
without
requiring
developers
to
drastically
change
their
workflow.
</p>
<p class="note">
The
example
above
does
not
use
the
<code>
@id
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
to
set
the
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
of
the
node
being
described
above.
This
type
of
node
is
called
an
<dfn title="unlabeled_node" id="dfn-unlabeled_node">
unlabeled
node
</dfn>
and
is
considered
to
be
a
weaker
form
of
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
It
is
advised
that
all
nodes
described
in
JSON-LD
are
given
unique
identifiers
via
the
<code>
@id
</code>
keyword
unless
the
data
is
not
intended
to
be
linked
to
from
other
data
sets.
</p>
<p>
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
used
to
define
property
values
is
called
a
<a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition">
subject
definition
</a>.
<a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition">
Subject
definitions
</a>
do
not
require
a
<code>
@id
</code>,
in
which
case
they
are
considered
to
be
an
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>.
</p>
</div>
</div>
<div id="iris" typeof="bibo:Chapter" resource="#iris" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
3.2
</span>
IRIs
</h3>
<p>
Expressing
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
are
fundamental
to
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
as
that
is
how
most
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
s,
all
<a class="tref internalDFN" title="property" href="#dfn-property">
properties
</a>
and
many
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
s
are
identified.
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
can
be
expressed
in
a
variety
of
different
ways
in
JSON-LD.
</p>
<ol>
<li>
Except
within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition,
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
in
the
key
position
in
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
that
have
a
mapping
to
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
another
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
in
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
are
expanded
to
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
by
JSON-LD
processors.
</li>
<li>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
generated
for
the
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
value
specified
using
<code>
@id
</code>
or
<code>
@type
</code>.
</li>
<li>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
generated
for
the
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
value
of
any
key
for
which
there
are
<a class="tref internalDFN" title="coercion" href="#dfn-coercion">
coercion
</a>
rules
in
effect
that
identify
the
value
as
an
<code>
@id
</code>.
</li>
</ol>
<p>
IRIs
may
be
represented
as
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
a
<a class="tref internalDFN" title="relative_iri" href="#dfn-relative_iri">
relative
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>,
or
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<p>
An
<dfn title="absolute_iri" id="dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
is
defined
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC3987">
RFC3987
</a>
</cite>
]
containing
a
<em>
scheme
</em>
along
with
<em>
path
</em>
and
optional
<em>
query
</em>
and
<em>
fragment
</em>
segments.
A
<dfn title="relative_iri" id="dfn-relative_iri">
relative
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
is
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
that
is
relative
some
other
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<del class="diff-old">;
in
the
case
of
</del>
</a>.
<ins class="diff-chg">In
</ins>
JSON-LD
<del class="diff-old">this
is
</del>
<ins class="diff-chg">all
</ins><a class="tref internalDFN" title="relative_iri" href="#dfn-relative_iri"><ins class="diff-chg">
relative
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a><ins class="diff-chg">
s
are
resolved
relative
to
</ins>
the
<dfn title="base_iri" id="dfn-base_iri">
base
<del class="diff-old">location
of
</del>
<abbr title="Internationalized Resource Identifier">
<ins class="diff-chg">IRI
</ins></abbr></dfn><ins class="diff-chg">
associated
with
</ins>
the
<del class="diff-old">document.
</del>
<ins class="diff-chg">document
(typically,
the
directory
that
contains
the
document
or
the
document
itself).
</ins>
</p>
<p>
IRIs
can
be
expressed
directly
in
the
key
position
like
so:
</p>
<del class="diff-old">{
...
  &quot;&quot;: &quot;Manu Sporny&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/name</span>&quot;: &quot;Manu Sporny&quot;,
...
</ins>
}
</pre>
<p>
In
the
example
above,
the
key
<code>
http://xmlns.com/foaf/0.1/name
</code>
is
interpreted
as
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
as
opposed
to
being
interpreted
as
a
<del class="diff-old">string.
</del>
<ins class="diff-chg">string
because
it
contains
a
colon
(
</ins><code>:</code><ins class="diff-chg">
)
delimiting
a
valid
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr><ins class="diff-chg">
scheme.
</ins>
</p>
<p>
Term
expansion
occurs
for
IRIs
if
the
value
matches
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
defined
within
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>:
</p>
<del class="diff-old">{
  &quot;&quot;:
  {
    &quot;&quot;
...
  },
  &quot;&quot;: &quot;Manu Sporny&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;<span class="diff">@context</span>&quot;:
  {
    &quot;<span class="diff">name</span>&quot;: &quot;<span class="diff">http://xmlns.com/foaf/0.1/name</span>&quot;
...
  },
  &quot;<span class="diff">name</span>&quot;: &quot;Manu Sporny&quot;,
  &quot;status&quot;: &quot;trollin'&quot;,
...
</ins>
}
</pre>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
<ins class="diff-new">Term
</ins></a><ins class="diff-new">
s
are
case
sensitive,
and
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
be
matched
using
a
case-sensitive
comparison.
</ins></p><p><ins class="diff-new">
JSON
keys
that
do
not
expand
to
an
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr><ins class="diff-new">
are
ignored,
or
removed
in
some
cases,
by
the
[
</ins><cite><a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API"><ins class="diff-new">
JSON-LD-API
</ins></a></cite><ins class="diff-new">
].
However,
JSON
keys
that
do
not
include
a
mapping
in
the
</ins><a class="tref internalDFN" title="context" href="#dfn-context"><ins class="diff-new">
context
</ins></a><ins class="diff-new">
are
still
considered
valid
expressions
in
JSON-LD
documents
-
the
keys
just
don't
have
any
machine-readable,
semantic
meaning.
</ins></p><p>
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
Prefix
</a>
es
are
expanded
when
the
form
of
the
value
<ins class="diff-new">is
a
</ins>
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
represented
as
<del class="diff-old">is
</del>
<ins class="diff-chg">a
</ins>
<code>
prefix:suffix
<del class="diff-old">,
</del>
</code>
<ins class="diff-chg">combination,
</ins>
and
the
prefix
matches
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
defined
within
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>:
</p>
<del class="diff-old">{
  &quot;&quot;:
  {
    &quot;&quot;
...
  },
  &quot;&quot;: &quot;Manu Sporny&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;<span class="diff">@context</span>&quot;:
  {
    &quot;<span class="diff">foaf</span>&quot;: &quot;<span class="diff">http://xmlns.com/foaf/0.1/</span>&quot;
...
  },
  &quot;<span class="diff">foaf:name</span>&quot;: &quot;Manu Sporny&quot;,
...
</ins>
}
</pre>
<p>
<del class="diff-old">Term
s
are
case
sensitive,
and
must
be
matched
using
a
case-sensitive
comparison.
Keys
that
do
not
expand
to
an
absolute
IRI
are
ignored.
</del>
<code>
foaf:name
</code>
above
will
automatically
expand
out
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/name
</code>.
See
<a href="#compact-iris">
Compact
IRIs
</a>
for
more
details.
</p>
<p>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
generated
when
a
<del class="diff-old">value
</del>
<ins class="diff-chg">JSON
object
</ins>
is
<del class="diff-old">associated
with
a
key
using
</del>
<ins class="diff-chg">used
in
</ins>
the
<ins class="diff-new">value
position
that
contains
an
</ins>
<code>
@id
</code>
keyword:
</p>
<del class="diff-old">{
...
  &quot;homepage&quot;: { &quot;&quot;: &quot;http://manu.sporny.org&quot; }
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;homepage&quot;: { &quot;<span class="diff">@id</span>&quot;: &quot;http://manu.sporny.org&quot; }
...
</ins>
}
</pre>
<p class="note">
Specifying
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
with
an
<code>
@id
</code>
key
is
used
to
identify
that
object
using
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
This
facility
<em class="rfc2119" title="may">
may
</em>
also
be
used
to
link
<del class="diff-old">a
subject
with
an
</del>
<ins class="diff-chg">to
another
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
</ins>
object
</a>
using
a
mechanism
called
<a class="tref internalDFN" title="embedding" href="#dfn-embedding">
embedding
</a>,
which
is
covered
in
the
section
titled
<a href="#embedding">
Embedding
</a>.
</p>
<p>
If
type
<a class="tref internalDFN" title="coercion" href="#dfn-coercion">
coercion
</a>
rules
are
specified
in
the
<code>
@context
</code>
for
a
particular
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
or
property
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
generated:
</p>
<del class="diff-old">
  &quot;@context&quot;:
  {
    ...
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
    ...
  }
...
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
...
</del>
<pre class="example">{<span class="diff">
<ins class="diff-chg">  &quot;@context&quot;:
  {
    ...
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
    ...
  }</span>
...
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
...
</ins>
}
</pre>
<p>
<del class="diff-old">Even
</del>
<ins class="diff-chg">In
the
example
above,
even
</ins>
though
the
value
<code>
http://manu.sporny.org/
</code>
is
<ins class="diff-new">expressed
as
</ins>
a
<ins class="diff-new">JSON
</ins>
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>,
the
type
<a class="tref internalDFN" title="coercion" href="#dfn-coercion">
coercion
</a>
rules
will
transform
the
value
into
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
when
processed
by
a
JSON-LD
Processor.
</p>
</div>
<div id="identifying-the-subject" typeof="bibo:Chapter" resource="#identifying-the-subject" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
3.3
</span>
Identifying
the
Subject
</h3>
<p>
To
be
able
to
externally
reference
<del class="diff-old">nodes,
</del>
<ins class="diff-chg">nodes
in
a
graph,
</ins>
it
is
important
that
each
node
has
an
unambiguous
identifier.
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
are
a
fundamental
concept
of
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>,
and
nodes
should
have
a
de-referencable
identifier
used
to
name
and
locate
them.
For
nodes
to
be
truly
linked,
de-referencing
the
identifier
should
result
in
a
representation
of
that
<del class="diff-old">node.
</del>
<ins class="diff-chg">node
(for
example,
using
a
URL
to
retrieve
a
web
page).
</ins>
Associating
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
with
a
node
tells
an
application
that
the
returned
document
contains
a
description
of
the
node
requested.
</p>
<p>
JSON-LD
documents
may
also
contain
descriptions
of
other
nodes,
so
it
is
necessary
to
be
able
to
uniquely
identify
each
node
which
may
be
externally
referenced.
</p>
<p>
A
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
of
an
object
in
JSON
is
declared
using
the
<code>
@id
</code>
key.
The
subject
is
the
first
piece
of
information
needed
by
the
JSON-LD
processor
in
order
to
create
the
(subject,
property,
object)
tuple,
also
known
as
a
triple.
</p>
<del class="diff-old">{
...
  &quot;&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;<span class="diff">@id</span>&quot;: &quot;<span class="diff">http://example.org/people#joebob</span>&quot;,
...
</ins>
}
</pre>
<p>
The
example
above
would
set
the
subject
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://example.org/people#joebob
</code>.
</p>
<p>
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
used
to
define
property
values
is
called
a
<a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition">
subject
definition
</a>.
<a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition">
Subject
definitions
</a>
do
not
require
<del class="diff-old">a
</del>
<ins class="diff-chg">an
</ins>
<code>
@id
<del class="diff-old">,
in
which
case
they
are
considered
to
be
</del>
</code>.
<ins class="diff-chg">A
</ins><a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition"><ins class="diff-chg">
subject
definition
</ins></a><ins class="diff-chg">
that
does
not
contain
an
</ins><code><ins class="diff-chg">
@id
</ins></code><ins class="diff-chg">
property
is
called
</ins>
an
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>.
</p>
<p class="note">
To
ensure
the
best
possible
performance,
it
is
a
best
practice
to
put
the
<code>
@id
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
before
other
key-value
pairs
in
an
object.
If
it
isn't
listed
first,
processors
have
to
save
each
key-value
pair
until
<code>
@id
</code>
is
processed
before
they
can
start
generating
triples.
Not
specifying
the
<code>
@id
</code>
keyword
first
creates
a
memory
and
complexity
burden
for
one-pass
processors.
</p>
</div>
<div id="specifying-the-type" typeof="bibo:Chapter" resource="#specifying-the-type" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
3.4
</span>
Specifying
the
Type
</h3>
<p>
The
type
of
a
particular
subject
can
be
specified
using
the
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>.
Specifying
the
type
in
this
way
will
generate
a
triple
of
the
form
(subject,
type,
type-
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
).
To
be
considered
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>,
types
<em class="rfc2119" title="must">
must
</em>
be
uniquely
identified
by
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<del class="diff-old">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;<span class="diff">@type</span>&quot;: &quot;<span class="diff">http://xmlns.com/foaf/0.1/Person</span>&quot;,
...
</ins>
}
</pre>
</div>
<div id="string-internationalization" typeof="bibo:Chapter" resource="#string-internationalization" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
3.5
</span>
String
Internationalization
</h3>
<p>
<del class="diff-old">In
different
scenarios
</del>
<ins class="diff-chg">At
times,
</ins>
it
is
important
to
annotate
a
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
with
its
language.
In
JSON-LD
this
is
possible
in
a
variety
of
ways.
Firstly,
it
is
possible
to
define
a
default
language
for
a
JSON-LD
document
by
setting
the
<code>
@language
</code>
key
in
the
<code>
@context
</code>
or
in
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
definition:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: ,
  &quot;occupation&quot;: 
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },</span>
  &quot;name&quot;: <span class="diff">&quot;花澄&quot;</span>,
  &quot;occupation&quot;: <span class="diff">&quot;科学者&quot;</span>
</ins>
}
</pre>
<p>
The
example
above
would
associate
the
<code>
ja
</code>
language
code
with
the
two
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
s
<em>
花澄
</em>
and
<em>
科学者
</em>.
Languages
<em class="rfc2119" title="must">
must
</em>
be
expressed
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-BCP47">
BCP47
</a>
</cite>
]
format.
</p>
<p>
It
is
possible
to
override
the
default
language
by
using
the
expanded
form
of
a
value:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;occupation&quot;: {
    &quot;@value&quot;: &quot;Scientist&quot;,
    &quot;@language&quot;: &quot;en&quot;
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;occupation&quot;: <span class="diff">{
    &quot;@value&quot;: &quot;Scientist&quot;,
    &quot;@language&quot;: &quot;en&quot;
  }</span>
</ins>
}
</pre>
<p>
It
is
also
possible
to
override
the
default
language
or
specify
a
plain
value
by
omitting
the
<code>
@language
</code>
tag
or
setting
it
to
<code>
null
</code>
when
expressing
the
expanded
value:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: {
    &quot;@value&quot;: &quot;花澄&quot;
  },
  &quot;occupation&quot;:  {
    &quot;@value&quot;: &quot;Ninja&quot;,
    &quot;@language&quot;: &quot;en&quot;
  },
  &quot;speciality&quot;: &quot;手裏剣&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: <span class="diff">{
    &quot;@value&quot;: &quot;Frank&quot;
  },</span>
  &quot;occupation&quot;: <span class="diff"> {
    &quot;@value&quot;: &quot;Ninja&quot;,
    &quot;@language&quot;: &quot;en&quot;
  }</span>,
  &quot;speciality&quot;: &quot;手裏剣&quot;
</ins>
}
</pre>
<p class="note">
Please
note
that
language
associations
<em class="rfc2119" title="must">
must
</em>
only
be
applied
to
plain
literal
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
s.
That
is,
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>
s
or
values
that
are
subject
to
<a href="#type-coercion">
type
coercion
</a>
won't
be
language
tagged.
</p>
<p>
To
clear
the
default
language
for
a
subtree,
<code>
@language
</code>
can
be
set
to
<code>
null
</code>
in
a
<a class="tref internalDFN" title="local_context" href="#dfn-local_context">
local
context
</a>
as
follows:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;details&quot;: {
    &quot;@context&quot;: {
      &quot;@language&quot;: null
    },
    &quot;occupation&quot;: &quot;Ninja&quot;
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;details&quot;: {
</ins><span class="diff">    &quot;@context&quot;: {<ins class="diff-chg">
      &quot;@language&quot;: null
    },</span>
    &quot;occupation&quot;: &quot;Ninja&quot;
  }
</ins>
}
</pre>
<p class="note">
JSON-LD
allows
<ins class="diff-new">one
</ins>
to
associate
language
information
with
<del class="diff-old">terms.
</del>
<a class="tref internalDFN" title="term" href="#dfn-term">
<ins class="diff-chg">term
</ins></a><ins class="diff-chg">
s.
</ins>
See
<a href="#expanded-term-definition">
Expanded
Term
Definition
</a>
for
more
details.
</p>
</div>
<div id="sets-and-lists" typeof="bibo:Chapter" resource="#sets-and-lists" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
3.6
</span>
Sets
and
Lists
</h3>
<p>
A
JSON-LD
author
can
express
multiple
values
in
a
compact
way
by
using
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
s.
<del class="diff-old">But,
because
</del>
<ins class="diff-chg">Since
</ins>
graphs
do
not
describe
ordering
for
links
between
nodes,
<del class="diff-old">in
contrast
to
plain
JSON,
</del>
arrays
in
JSON-LD
do
not
provide
an
ordering
of
the
listed
objects
by
default.
<ins class="diff-new">This
is
exactly
the
opposite
from
regular
JSON
arrays,
which
are
ordered
by
default.
</ins>
For
example,
consider
the
following
simple
document:
</p>
<del class="diff-old">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: ,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: <span class="diff">[ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]</span>,
...
</ins>
}
</pre>
<p>
The
markup
shown
above
would
result
in
three
triples
being
generated,
each
relating
the
subject
to
an
individual
object,
with
no
inherent
order:
</p>
<del class="diff-old">&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;joe&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;bob&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
</del>
<pre class="example">&lt;http://example.org/people#joebob&gt;
<ins class="diff-chg">   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;joe&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;bob&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
</ins>
&quot;jaybee&quot;
.
</pre>
<p>
Multiple
values
may
also
be
expressed
using
the
expanded
object
form:
</p>
<del class="diff-old">{
  &quot;@id&quot;: &quot;http://example.org/articles/8&quot;,
  &quot;dc:title&quot;: 
  [
    {
      &quot;@value&quot;: &quot;Das Kapital&quot;,
      &quot;@language&quot;: &quot;de&quot;
    },
    {
      &quot;@value&quot;: &quot;Capital&quot;,
      &quot;@language&quot;: &quot;en&quot;
    }
  ]
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@id&quot;: &quot;http://example.org/articles/8&quot;,
  &quot;dc:title&quot;: <span class="diff">
  [
    {
      &quot;@value&quot;: &quot;Das Kapital&quot;,
      &quot;@language&quot;: &quot;de&quot;
    },
    {
      &quot;@value&quot;: &quot;Capital&quot;,
      &quot;@language&quot;: &quot;en&quot;
    }
  ]</span>
</ins>
}
</pre>
<p>
The
markup
shown
above
would
generate
the
following
triples,
again
with
no
inherent
order:
</p>
<del class="diff-old">&lt;http://example.org/articles/8&gt;
   &lt;http://purl.org/dc/terms/title&gt;
      &quot;Das Kapital&quot;@de .
&lt;http://example.org/articles/8&gt;
   &lt;http://purl.org/dc/terms/title&gt;
</del>
<pre class="example">&lt;http://example.org/articles/8&gt;
<ins class="diff-chg">   &lt;http://purl.org/dc/terms/title&gt;
      &quot;Das Kapital&quot;@de .
&lt;http://example.org/articles/8&gt;
   &lt;http://purl.org/dc/terms/title&gt;
</ins>
&quot;Capital&quot;@en
.
</pre>
<p>
As
the
notion
of
ordered
collections
is
rather
important
in
data
modeling,
it
is
useful
to
have
specific
language
support.
In
JSON-LD,
a
list
may
be
represented
using
the
<code>
@list
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
as
follows:
</p>
<del class="diff-old">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;foaf:nick&quot;:
  {
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]
  },
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;foaf:nick&quot;:
</ins>  <span class="diff">{<ins class="diff-chg">
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]
  }</span>,
...
</ins>
}
</pre>
<p>
This
describes
the
use
of
this
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
as
being
ordered,
and
order
is
maintained
<del class="diff-old">through
operations
such
as
Expansion
,
Compaction
,
and
Framing
.
</del>
<ins class="diff-chg">when
processing
a
document.
</ins>
If
every
use
of
a
given
multi-valued
property
is
a
list,
this
may
be
abbreviated
by
setting
<code>
@container
</code>
to
<code>
@list
</code>
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ...
    &quot;nick&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/nick&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }
  },
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: ,
...
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  {
    ...
    &quot;nick&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/nick&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }
  }</span>,
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: <span class="diff">[ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]</span>,
...
</ins>
}
</pre>
<p class="note">
List
of
lists
are
not
allowed
in
this
version
of
JSON-LD.
If
a
list
of
lists
is
detected,
a
JSON-LD
processor
will
throw
an
exception.
<ins class="diff-new">This
decision
was
made
due
to
the
extreme
amount
of
added
complexity
when
processing
lists
of
lists.
</ins>
</p>
<p>
Similarly
to
<code>
@list
</code>,
there
exists
the
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
<code>
@set
</code>
to
describe
unordered
sets.
While
its
use
in
the
body
of
a
JSON-LD
document
represents
just
syntactic
sugar
that
<em class="rfc2119" title="must">
must
</em>
be
optimized
away
when
processing
the
document,
it
is
very
helpful
<del class="diff-old">for
Compaction
and
Framing
.
The
value
</del>
<ins class="diff-chg">when
used
within
the
context
of
a
document.
Values
</ins>
of
terms
associated
with
a
<code>
@set
</code>
<del class="diff-old">-
</del>
or
<code>
@list
</code>
<del class="diff-old">-
@container
</del>
<ins class="diff-chg">container
</ins>
are
always
represented
in
the
form
of
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
-
even
if
there
is
just
a
single
<del class="diff-old">value.
</del>
<ins class="diff-chg">value
that
would
otherwise
be
optimized
to
a
non-array
form
in
a
</ins><a href="#compact-document-form"><ins class="diff-chg">
compacted
document
</ins></a>.
This
makes
post-processing
of
the
data
easier
as
the
data
is
<ins class="diff-new">always
</ins>
in
<ins class="diff-new">array
form,
even
if
the
array
only
contains
</ins>
a
<del class="diff-old">deterministic
form.
If
no
such
@container
is
specified,
</del>
single
<del class="diff-old">values
are
optimized
to
a
non-array
form.
</del>
<ins class="diff-chg">value.
</ins>
</p>
<p class="note">
The
use
of
<code>
@container
</code>
in
the
body
of
a
JSON-LD
document,
i.e.,
outside
<code>
@context
</code>
<del class="diff-old">is
</del>
<em class="rfc2119" title="must">
<ins class="diff-chg">must
</ins></em><ins class="diff-chg">
be
</ins>
ignored
by
JSON-LD
processors.
</p>
</div>
</div>
<div id="advanced-concepts" typeof="bibo:Chapter" resource="#advanced-concepts" rel="bibo:chapter" class="section">
<h2>
<span class="secno">
4.
</span>
Advanced
Concepts
</h2>
<p>
JSON-LD
has
a
number
of
features
that
provide
functionality
above
and
beyond
the
core
functionality
described
above.
The
following
<del class="diff-old">sections
outline
the
features
that
are
specific
to
JSON-LD.
</del>
<ins class="diff-chg">section
describes
this
advanced
functionality
in
more
detail.
</ins>
</p>
<div id="typed-values" typeof="bibo:Chapter" resource="#typed-values" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.1
</span>
Typed
Values
</h3>
<p>
A
value
with
an
associated
type,
also
known
as
a
<dfn title="typed_value" id="dfn-typed_value">
typed
value
</dfn>,
is
indicated
by
associating
a
value
with
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
which
indicates
the
value's
type.
Typed
values
may
be
expressed
in
JSON-LD
in
three
ways:
</p>
<ol>
<li>
By
utilizing
the
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
when
defining
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
within
a
<code>
@context
</code>
section.
</li>
<li>
By
utilizing
the
expanded
form
for
specifying
objects.
</li>
<li>
By
using
a
native
JSON
type.
</li>
</ol>
<p>
The
first
example
uses
the
<code>
@type
</code>
keyword
to
<del class="diff-old">express
</del>
<ins class="diff-chg">associate
</ins>
a
<del class="diff-old">typed
value:
</del>
<ins class="diff-chg">type
with
a
particular
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a><ins class="diff-chg">
in
the
</ins><code><ins class="diff-chg">
@context
</ins></code>:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;modified&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/modified&quot;,
      &quot;@type&quot;: &quot;xsd:dateTime&quot;
    }
  }
...
  &quot;modified&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
...
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  {
    &quot;modified&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/modified&quot;,
      &quot;@type&quot;: &quot;http://www.w3.org/2001/XMLSchema#dateTime&quot;
    }
  },</span>
...
  &quot;modified&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
...
</ins>
}
</pre>
<p>
The
<em>
<ins class="diff-new">modified
</ins></em><ins class="diff-new">
key's
value
above
is
automatically
type
coerced
to
a
datetime
value
because
of
the
information
specified
in
the
</ins><code><ins class="diff-new">
@context
</ins></code>.</p><p><ins class="diff-new">
The
</ins>
second
example
uses
the
expanded
form
<del class="diff-old">for
specifying
objects:
</del>
<ins class="diff-chg">of
setting
the
type
information
in
the
body
of
a
JSON-LD
document:
</ins>
</p>
<del class="diff-old">{
...
  &quot;modified&quot;:
  {
    &quot;@value&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
    &quot;@type&quot;: &quot;xsd:dateTime&quot;
  }
...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;modified&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/modified&quot;
    }
  },
...
  &quot;modified&quot;:
</ins>  <span class="diff">{<ins class="diff-chg">
    &quot;@value&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
    &quot;@type&quot;: &quot;http://www.w3.org/2001/XMLSchema#dateTime&quot;
  }</span>
...
</ins>
}
</pre>
<p>
Both
examples
above
would
generate
an
object
with
the
value
of
<code>
2010-05-29T14:17:39+02:00
</code>
and
the
type
of
<code>
http://www.w3.org/2001/XMLSchema#dateTime
</code>.
</p>
<p>
The
third
example
uses
a
built-in
native
JSON
type,
a
<a class="tref internalDFN" title="number" href="#dfn-number">
number
</a>,
to
express
a
type:
</p>
<del class="diff-old">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;age&quot;: 
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;age&quot;: <span class="diff">31</span>
...
</ins>
}
</pre>
<p>
The
example
above
is
really
just
a
shorthand
for
the
following:
</p>
<del class="diff-old">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;age&quot;:
  {
    &quot;@value&quot;: &quot;31&quot;,
    &quot;@type&quot;: &quot;http://www.w3.org/2001/XMLSchema#integer&quot;
  }
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;age&quot;:
</ins>  <span class="diff">{<ins class="diff-chg">
    &quot;@value&quot;: &quot;31&quot;,
    &quot;@type&quot;: &quot;http://www.w3.org/2001/XMLSchema#integer&quot;
  }</span>
...
</ins>
}
</pre>
<p class="note">
The
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
is
also
used
to
associate
a
type
with
a
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>.
Although
the
same
keyword
is
used
in
both
places,
the
concept
of
an
<em>
object
type
</em>
and
a
<em>
value
type
</em>
are
different.
This
is
similar
to
object-oriented
programming
languages
where
both
scalar
and
structured
types
use
the
same
class
inheritance
mechanism,
even
though
scalar
types
and
structured
types
are
inherently
different.
</p>
</div>
<div id="compact-iris" typeof="bibo:Chapter" resource="#compact-iris" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.2
</span>
Compact
IRIs
</h3>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
in
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
documents
may
draw
from
a
number
of
different
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>.
At
times,
declaring
every
single
term
that
a
document
uses
can
require
the
developer
to
declare
tens,
if
not
hundreds
of
potential
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
that
are
used
across
an
application.
This
is
a
concern
for
at
least
<del class="diff-old">three
</del>
<ins class="diff-chg">two
</ins>
reasons:
the
first
is
the
cognitive
load
on
the
developer
of
remembering
all
of
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s,
<ins class="diff-new">and
</ins>
the
second
is
the
serialized
size
of
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
if
it
is
specified
<del class="diff-old">inline,
the
third
is
future-proofing
embedded
application
context
s
that
may
not
be
easy
to
change
after
they
are
deployed.
</del>
<ins class="diff-chg">inline.
</ins>
In
order
to
address
these
issues,
the
concept
of
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
introduced.
</p>
<p>
A
<dfn title="compact_iri" id="dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
is
a
way
of
expressing
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
using
a
<em>
prefix
</em>
and
<em>
suffix
<del class="diff-old">.
Generally,
these
prefixes
are
used
by
concatenating
the
prefix
</del>
</em>
<del class="diff-old">and
a
suffix
,
which
is
</del>
separated
by
a
colon
(
<code>:
</code>
<del class="diff-old">).
</del>
<ins class="diff-chg">)
which
is
similar
to
the
</ins><cite><a href="http://www.w3.org/TR/rdfa-core/#s_curies"><ins class="diff-chg">
CURIE
Syntax
</ins></a></cite><ins class="diff-chg">
in
[
</ins><cite><a class="bibref" rel="biblioentry" href="#bib-RDFA-CORE"><ins class="diff-chg">
RDFA-CORE
</ins></a></cite><ins class="diff-chg">
].
</ins>
The
<dfn title="prefix" id="dfn-prefix">
prefix
</dfn>
is
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
taken
from
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
and
is
a
short
string
identifying
a
particular
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
in
a
JSON-LD
document.
For
example,
the
prefix
<code>
foaf
</code>
may
be
used
as
a
short
hand
for
the
Friend-of-a-Friend
vocabulary,
which
is
identified
using
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/
</code>.
A
developer
may
append
any
of
the
FOAF
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
terms
to
the
end
of
the
prefix
to
specify
a
short-hand
version
of
the
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
for
the
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
term.
For
example,
<code>
foaf:name
</code>
would
be
expanded
out
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/name
</code>.
Instead
of
having
to
remember
and
type
out
the
entire
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
the
developer
can
instead
use
the
prefix
in
their
JSON-LD
markup.
</p>
<p>
Terms
are
interpreted
as
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
if
they
contain
at
least
one
colon
and
the
first
colon
is
not
followed
by
two
slashes
(
<code>
//
</code>,
as
in
<code>
http://example.com
</code>
).
To
generate
the
full
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
the
value
is
first
split
into
a
<em>
prefix
</em>
and
<em>
suffix
</em>
at
the
first
occurrence
of
a
colon
(
<code>:
</code>
).
If
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
contains
a
term
mapping
for
<em>
prefix
</em>,
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
generated
by
prepending
the
mapped
<em>
prefix
</em>
to
the
(possibly
empty)
<em>
suffix
</em>
using
textual
concatenation.
If
no
prefix
mapping
is
defined,
the
value
is
interpreted
as
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
If
the
prefix
is
an
underscore
(
<code>
_
</code>
),
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
remains
unchanged.
This
effectively
means
that
every
term
containing
a
colon
will
be
interpreted
by
a
JSON-LD
processor
as
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>.
</p>
<p>
<del class="diff-old">The
ability
to
use
compact
IRIs
reduces
the
need
for
developers
to
declare
every
vocabulary
term
that
they
intend
to
use
in
the
JSON-LD
context
.
This
reduces
stand-alone
JSON-LD
document
serialization
size
because
every
vocabulary
term
need
not
be
declared
in
the
embedded
context.
Compact
IRIs
also
reduces
the
cognitive
load
on
the
developer.
It
is
far
easier
to
remember
foaf:name
than
it
is
to
remember
http://xmlns.com/foaf/0.1/name
.
The
use
of
prefixes
also
ensures
that
a
context
document
does
not
have
to
be
updated
in
lock-step
with
an
externally
defined
vocabulary
.
Without
prefixes,
a
developer
would
need
to
keep
their
application
context
terms
in
lock-step
with
an
externally
defined
vocabulary.
Rather,
by
just
declaring
the
vocabulary
prefix,
one
can
use
new
terms
as
they're
declared
without
having
to
update
the
application's
JSON-LD
context
.
</del>
Consider
the
following
example:
</p>
<del class="diff-old">  {
  &quot;@context&quot;:
  {
    
    
  },
  &quot;@id&quot;: &quot;http://example.org/library&quot;,
  &quot;@type&quot;: ,
  :
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,
    &quot;@type&quot;: ,
    : &quot;Plato&quot;,
    : &quot;The Republic&quot;,
    :
    {
      &quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,
      &quot;@type&quot;: ,
      : &quot;An introductory chapter on The Republic.&quot;,
      : &quot;The Introduction&quot;
    }
  }
</del>
  <pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;dc&quot;: &quot;http://purl.org/dc/elements/1.1/&quot;,</span>    <span class="diff">&quot;ex&quot;: &quot;http://example.org/vocab#&quot;</span><ins class="diff-chg">
  },
  &quot;@id&quot;: &quot;http://example.org/library&quot;,
  &quot;@type&quot;: <span class="diff">&quot;ex:Library&quot;</span>,
</ins>  <span class="diff">&quot;ex:contains&quot;</span>:<ins class="diff-chg">
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,
    &quot;@type&quot;: <span class="diff">&quot;ex:Book&quot;</span>,
</ins>    <span class="diff">&quot;dc:creator&quot;</span>: &quot;Plato&quot;,    <span class="diff">&quot;dc:title&quot;</span>: &quot;The Republic&quot;,    <span class="diff">&quot;ex:contains&quot;</span>:<ins class="diff-chg">
    {
      &quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,
      &quot;@type&quot;: <span class="diff">&quot;ex:Chapter&quot;</span>,
</ins>      <span class="diff">&quot;dc:description&quot;</span>: &quot;An introductory chapter on The Republic.&quot;,      <span class="diff">&quot;dc:title&quot;</span>: &quot;The Introduction&quot;<ins class="diff-chg">
    }
  }
</ins>
}
</pre>
<p>
In
this
example,
two
different
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>
are
referred
to
using
prefixes.
Those
prefixes
are
then
used
as
type
and
property
values
using
the
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
prefix:suffix
</code>
notation.
</p>
<p>
It's
also
possible
to
use
compact
IRIs
within
the
context
as
shown
in
the
following
example:
</p>
<del class="diff-old">  {
  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    : { &quot;@type&quot;: &quot;@id&quot; },
    &quot;picture&quot;: { &quot;@id&quot;: , &quot;@type&quot;: &quot;@id&quot; }
  },
  &quot;@subject&quot;: &quot;http://me.markus-lanthaler.com/&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;foaf:homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;picture&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
</del>
  <pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
</ins>    <span class="diff">&quot;foaf:homepage&quot;</span>: { &quot;@type&quot;: &quot;@id&quot; },<ins class="diff-chg">
    &quot;picture&quot;: { &quot;@id&quot;: <span class="diff">&quot;foaf:depiction&quot;</span>, &quot;@type&quot;: &quot;@id&quot; }
  },
  &quot;@subject&quot;: &quot;http://me.markus-lanthaler.com/&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;foaf:homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;picture&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
</ins>
}
</pre>
<del class="diff-old">Compact
IRIs
,
also
known
as
CURIEs,
are
defined
more
formally
in
RDFa
Core
1.1,
Section
6
&quot;CURIE
Syntax
Definition&quot;
[
RDFA-CORE
].
JSON-LD
does
not
support
the
square-bracketed
CURIE
syntax
as
the
mechanism
is
not
required
to
disambiguate
IRI
s
in
a
JSON-LD
document
like
it
is
in
HTML
documents.
</del>
</div>
<div id="external-contexts" typeof="bibo:Chapter" resource="#external-contexts" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.3
</span>
External
Contexts
</h3>
<p>
Authors
may
choose
to
declare
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
s
in
external
documents
to
promote
re-use
of
contexts
as
well
as
reduce
the
size
of
JSON-LD
documents.
</p>
<p>
In
order
to
use
an
external
context,
an
author
<em class="rfc2119" title="must">
must
</em>
specify
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
to
a
valid
JSON-LD
document.
The
referenced
document
<em class="rfc2119" title="must">
must
</em>
have
a
top-level
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>.
The
value
of
any
<code>
@context
</code>
key
within
that
object
is
substituted
for
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
within
the
referencing
document
to
have
the
same
effect
as
if
the
value
were
specified
inline
within
the
referencing
document.
</p>
<p>
The
following
example
demonstrates
the
use
of
an
external
context:
</p>
<del class="diff-old">{
  ,
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;: &quot;http://json-ld.org/contexts/person&quot;</span>,
<ins class="diff-chg">  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<p>
Authors
may
also
import
multiple
contexts
or
a
combination
of
external
and
local
contexts
by
specifying
a
list
of
contexts:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  [
    &quot;http://json-ld.org/contexts/person&quot;,
    {
      &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
    },
    &quot;http://json-ld.org/contexts/event&quot;,
  ]
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
  &quot;celebrates&quot;:
  {
    &quot;@type&quot;: &quot;Event&quot;,
    &quot;description&quot;: &quot;International Talk Like a Pirate Day&quot;,
    &quot;date&quot;: &quot;R/2011-09-19&quot;
  }
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  [
    &quot;http://json-ld.org/contexts/person&quot;,
    {
      &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
    },
    &quot;http://json-ld.org/contexts/event&quot;,
  ]</span>
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>  <span class="diff">&quot;celebrates&quot;:<ins class="diff-chg">
  {
    &quot;@type&quot;: &quot;Event&quot;,
    &quot;description&quot;: &quot;International Talk Like a Pirate Day&quot;,
    &quot;date&quot;: &quot;R/2011-09-19&quot;
  }</span>
</ins>
}
</pre>
<p>
Each
context
in
a
list
will
be
evaluated
in-order.
Duplicate
mappings
among
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
s
<em class="rfc2119" title="must">
must
</em>
be
overwritten
on
a
last-defined-overrides
basis.
The
context
list
<em class="rfc2119" title="must">
must
</em>
contain
either
de-referenceable
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
or
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
s
that
conform
to
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
syntax
as
described
in
this
document.
</p>
<p>
An
author
<em class="rfc2119" title="may">
may
</em>
nest
contexts
within
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
s,
with
the
more
deeply
nested
contexts
overriding
the
values
in
previously
defined
contexts:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://example.com/person#name&quot;,
    &quot;details&quot;: &quot;http://example.com/person#details&quot;
  },
  &quot;&quot;: &quot;Markus Lanthaler&quot;,
  ...
  &quot;details&quot;:
  {
    
    &quot;&quot;: &quot;Graz University of Technology&quot;
  }
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  {
    &quot;name&quot;: &quot;http://example.com/person#name&quot;,
    &quot;details&quot;: &quot;http://example.com/person#details&quot;
  },</span>
  &quot;<span class="diff">name</span>&quot;: &quot;Markus Lanthaler&quot;,
  ...
  &quot;details&quot;:
  {
</ins>    <span class="diff">&quot;@context&quot;: {<ins class="diff-chg">
      &quot;name&quot;: &quot;http://example.com/organization#name&quot;
    },</span>
    &quot;<span class="diff">name</span>&quot;: &quot;Graz University of Technology&quot;
  }
</ins>
}
</pre>
<p>
In
the
example
above,
the
<code>
name
</code>
prefix
is
overridden
in
the
more
deeply
nested
<code>
details
</code>
structure.
Note
that
this
is
rarely
a
good
authoring
practice
and
is
typically
used
when
the
JSON
object
has
legacy
applications
using
the
structure
of
the
object.
</p>
<p>
External
JSON-LD
context
documents
<em class="rfc2119" title="may">
may
</em>
contain
extra
information
located
outside
of
the
<code>
@context
</code>
key,
such
as
documentation
about
the
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefixes
</a>
declared
in
the
document.
When
importing
a
<code>
@context
</code>
value
from
an
external
JSON-LD
context
document,
any
extra
information
contained
outside
of
the
<code>
@context
</code>
value
<em class="rfc2119" title="must">
must
</em>
be
discarded.
It
is
also
<em class="rfc2119" title="recommended">
recommended
</em>
that
a
human-readable
document
<del class="diff-old">encoded
in
HTML+RDFa
[
HTML-RDFA
]
or
other
Linked
Data
compatible
format
</del>
is
served
as
well
to
explain
the
correct
usage
of
the
JSON-LD
context
document.
</p>
</div>
<div id="referencing-contexts-from-json-documents" typeof="bibo:Chapter" resource="#referencing-contexts-from-json-documents" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.4
</span>
Referencing
Contexts
from
JSON
Documents
</h3>
<p>
Ordinary
JSON
documents
can
be
transformed
into
JSON-LD
documents
by
referencing
to
an
external
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
in
an
HTTP
Link
Header.
Doing
this
allows
JSON
to
be
unambiguously
machine-readable
without
requiring
developers
to
drastically
change
their
workflow
and
provides
an
upgrade
path
for
existing
infrastructure
without
breaking
existing
clients
that
rely
on
the
<code>
application/json
</code>
media
type.
</p>
<p>
In
order
to
use
an
external
context
with
an
ordinary
JSON
document,
an
author
<em class="rfc2119" title="must">
must
</em>
specify
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
to
a
valid
JSON-LD
document
in
an
HTTP
Link
Header
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC5988">
RFC5988
</a>
</cite>
]
using
the
<code>
describedby
</code>
link
relation.
The
referenced
document
<em class="rfc2119" title="must">
must
</em>
have
a
top-level
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>.
The
<code>
@context
</code>
subtree
within
that
object
is
added
to
the
top-level
object
of
the
referencing
document.
If
an
array
is
at
the
top-level
of
the
referencing
document
and
its
items
are
objects,
the
<code>
@context
</code>
subtree
is
added
to
all
array
items.
All
extra
information
located
outside
of
the
<code>
@context
</code>
subtree
in
the
referenced
document
<em class="rfc2119" title="must">
must
</em>
be
discarded.
</p>
<p>
The
following
example
demonstrates
the
use
of
an
external
context
with
an
ordinary
JSON
document:
</p>
<del class="diff-old">GET /ordinary-json-document.json HTTP/1.1
Host: example.com
Accept: application/json,*/*;q=0.1

====================================

HTTP/1.0 200 OK
...
Content-Type: application/json


{
  &quot;name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
</del>
<pre class="example">GET /ordinary-json-document.json HTTP/1.1
<ins class="diff-chg">Host: example.com
Accept: application/ld+json,application/json,*/*;q=0.1
====================================
HTTP/1.0 200 OK
...
Content-Type: <span class="diff">application/json</span>
</ins><span class="diff">Link: &lt;http://json-ld.org/contexts/person&gt;; rel=&quot;describedby&quot;; type=&quot;application/ld+json&quot;</span><ins class="diff-chg">
{
  &quot;name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
</ins>
}
</pre>
<p class="note">
JSON-LD
documents
served
with
the
<code>
application/ld+json
</code>
media
type
<em class="rfc2119" title="must">
must
</em>
have
all
context
information,
including
references
to
external
contexts,
within
the
body
of
the
document.
</p>
</div>
<div id="expanded-term-definition" typeof="bibo:Chapter" resource="#expanded-term-definition" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.5
</span>
Expanded
Term
Definition
</h3>
<p>
Within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition,
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
<em class="rfc2119" title="may">
may
</em>
be
defined
using
an
expanded
notation
to
allow
for
additional
information
associated
with
the
term
to
be
specified
(see
also
<a href="#type-coercion">
Type
Coercion
</a>
and
<a href="#sets-and-lists">
Sets
and
Lists
</a>
).
</p>
<p>
Instead
of
using
a
string
representation
of
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<em class="rfc2119" title="may">
may
</em>
be
specified
using
an
object
having
an
<code>
@id
</code>
key.
The
value
of
the
<code>
@id
</code>
key
<em class="rfc2119" title="must">
must
</em>
be
either
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>,
a
<del class="diff-old">prefix
:suffix
value,
</del>
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
<ins class="diff-chg">compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a>,
or
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
<del class="diff-old">Type
information
may
be
specified
</del>
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: ,
    &quot;name&quot;: ,
    &quot;homepage&quot;: ,
    &quot;depiction&quot;: 
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: <span class="diff">{ &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/&quot; }</span>,
    &quot;name&quot;: <span class="diff">{ &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot; }</span>,
    &quot;homepage&quot;: <span class="diff">{ &quot;@id&quot;: &quot;foaf:homepage&quot; }</span>,
    &quot;depiction&quot;: <span class="diff">{ &quot;@id&quot;: &quot;foaf:depiction&quot; }</span>
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<p>
This
allows
additional
information
to
be
associated
with
the
term.
This
<em class="rfc2119" title="may">
may
</em>
be
used
for
<a href="#type-coercion">
Type
Coercion
</a>,
<a href="#sets-and-lists">
Sets
and
Lists
</a>
),
or
to
associate
language
information
with
a
term
as
shown
in
the
following
example:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    ...
    &quot;ex&quot;: &quot;http://example.com/&quot;,
    &quot;@language&quot;: &quot;ja&quot;,
    &quot;name&quot;: { &quot;@id&quot;: &quot;ex:name&quot;,  },
    &quot;occupation&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot; },
    &quot;occupation_en&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot;,  },
    &quot;occupation_de&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot;,  }
  },
  &quot;name&quot;: &quot;Yagyū Muneyoshi&quot;,
  &quot;occupation&quot;: &quot;忍者&quot;,
  &quot;occupation_en&quot;: &quot;Ninja&quot;,
  &quot;occupation_cs&quot;: &quot;Nindža&quot;,
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    ...
    &quot;ex&quot;: &quot;http://example.com/&quot;,
    &quot;@language&quot;: &quot;ja&quot;,
    &quot;name&quot;: { &quot;@id&quot;: &quot;ex:name&quot;, <span class="diff">&quot;@language&quot;: null</span> },
    &quot;occupation&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot; },
    &quot;occupation_en&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot;, <span class="diff">&quot;@language&quot;: &quot;en&quot;</span> },
    &quot;occupation_cs&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot;, <span class="diff">&quot;@language&quot;: &quot;cs&quot;</span> }
  },
</ins>  <span class="diff">&quot;name&quot;: &quot;Yagyū Muneyoshi&quot;,<ins class="diff-chg">
  &quot;occupation&quot;: &quot;忍者&quot;,
  &quot;occupation_en&quot;: &quot;Ninja&quot;,
  &quot;occupation_cs&quot;: &quot;Nindža&quot;,</span>
  ...
</ins>
}
</pre>
<p>
The
example
above
would
associate
<em>
忍者
</em>
with
the
specified
default
language
code
<code>
ja
</code>,
<em>
Ninja
</em>
with
the
language
code
<code>
en
</code>,
and
<em>
Nindža
</em>
with
the
language
code
<code>
cs
</code>.
The
value
of
<code>
name
</code>,
<em>
Yagyū
Muneyoshi
</em>
wouldn't
be
associated
with
any
language
code
since
<del class="diff-old">it
</del>
<code>
<ins class="diff-chg">@language
</ins></code>
was
reset
<ins class="diff-new">to
</ins><a class="tref internalDFN" title="null" href="#dfn-null"><ins class="diff-new">
null
</ins></a>
in
the
expanded
term
definition.
</p>
<p>
Expanded
terms
<em class="rfc2119" title="may">
may
</em>
also
be
defined
using
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
<del class="diff-old">Compact
</del>
<ins class="diff-chg">compact
</ins>
IRIs
</a>
or
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
<ins class="diff-chg">absolute
</ins>
IRIs
</a>
as
keys.
If
the
definition
does
not
include
an
<code>
@id
</code>
key,
the
expanded
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
determined
by
performing
expansion
of
the
key
within
the
current
active
context.
<ins class="diff-new">This
mechanism
is
mainly
used
to
associate
type
or
language
information
with
a
</ins><a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri"><ins class="diff-new">
compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
or
an
</ins><a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri"><ins class="diff-new">
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>.
</p>
<p class="note">
<del class="diff-old">Although
</del>
<ins class="diff-chg">While
</ins>
it
is
possible
to
define
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
or
<ins class="diff-new">an
absolute
</ins>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
to
expand
to
some
other
<ins class="diff-new">unrelated
</ins>
<abbr title="Internationalized Resource Identifier">
IRI
<del class="diff-old">,
</del>
</abbr>
<ins class="diff-chg">(for
example,
</ins><code><ins class="diff-chg">
foaf:name
</ins></code><ins class="diff-chg">
expanding
to
</ins><code><ins class="diff-chg">
http://example.org/unrelated#species
</ins></code><ins class="diff-chg">
),
</ins>
such
usage
is
strongly
discouraged.
</p>
</div>
<div id="type-coercion" typeof="bibo:Chapter" resource="#type-coercion" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.6
</span>
Type
Coercion
</h3>
<p>
JSON-LD
supports
the
coercion
of
values
to
particular
data
types.
Type
<dfn title="coercion" id="dfn-coercion">
coercion
</dfn>
allows
someone
deploying
JSON-LD
to
coerce
the
incoming
or
outgoing
<del class="diff-old">types
</del>
<ins class="diff-chg">values
</ins>
to
the
proper
data
type
based
on
a
mapping
of
data
type
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
to
<del class="diff-old">property
types.
</del>
<a class="tref internalDFN" title="term" href="#dfn-term">
<ins class="diff-chg">term
</ins></a><ins class="diff-chg">
s.
</ins>
Using
type
coercion,
value
representation
is
preserved
without
requiring
the
data
type
to
be
specified
with
each
<del class="diff-old">usage.
</del>
<ins class="diff-chg">piece
of
data.
</ins>
</p>
<p>
Type
coercion
is
specified
within
an
<a href="#expanded-term-definition">
expanded
term
definition
</a>
using
the
<code>
@type
</code>
key.
The
<del class="diff-old">values
</del>
<ins class="diff-chg">value
</ins>
of
this
key
<del class="diff-old">represent
</del>
<ins class="diff-chg">represents
a
</ins>
type
<del class="diff-old">IRIs
</del>
<abbr title="Internationalized Resource Identifier">
<ins class="diff-chg">IRI
</ins></abbr>
and
<em class="rfc2119" title="must">
must
</em>
take
the
form
of
<ins class="diff-new">a
</ins>
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>,
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
or
the
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
<code>
@id
</code>.
Specifying
<code>
@id
</code>
indicates
that
within
the
body
of
a
JSON-LD
document,
<ins class="diff-new">a
</ins>
string
<del class="diff-old">values
</del>
<ins class="diff-chg">value
</ins>
of
<del class="diff-old">keys
</del>
<ins class="diff-chg">a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a>
coerced
<del class="diff-old">as
</del>
<ins class="diff-chg">to
</ins>
<code>
@id
</code>
<del class="diff-old">are
</del>
<ins class="diff-chg">is
</ins>
to
be
interpreted
as
<ins class="diff-new">an
</ins>
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<del class="diff-old">s.
</del>
</a>.
</p>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Terms
</a>
or
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>
used
as
the
value
of
a
<code>
@type
</code>
key
<em class="rfc2119" title="may">
may
</em>
be
defined
within
the
same
context.
<ins class="diff-new">This
means
that
one
may
specify
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins></a><ins class="diff-new">
like
</ins><code><ins class="diff-new">
xsd
</ins></code><ins class="diff-new">
and
then
use
</ins><code><ins class="diff-new">
xsd:integer
</ins></code><ins class="diff-new">
within
the
same
context
definition
-
the
JSON-LD
processor
will
be
able
to
determine
the
proper
expansion
for
</ins><code><ins class="diff-new">
xsd:integer
</ins></code>.
</p>
<p>
The
example
below
demonstrates
how
a
JSON-LD
author
can
coerce
values
to
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>
s,
IRIs
and
lists.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }
  },
  &quot;name&quot;: &quot;John Smith&quot;,
  &quot;age&quot;: ,
  &quot;homepage&quot;:
  [
    &quot;http://personal.example.org/&quot;,
    &quot;http://work.example.com/jsmith/&quot;
  ]
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
</ins>    <span class="diff">{<ins class="diff-chg">
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    }</span>,
    &quot;homepage&quot;:
</ins>    <span class="diff">{<ins class="diff-chg">
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }</span>
  },
  &quot;name&quot;: &quot;John Smith&quot;,
  &quot;age&quot;: <span class="diff">&quot;41&quot;</span>,
  &quot;homepage&quot;:
</ins>  <span class="diff">[<ins class="diff-chg">
    &quot;http://personal.example.org/&quot;,
    &quot;http://work.example.com/jsmith/&quot;
  ]</span>
</ins>
}
</pre>
<p>
The
example
above
would
generate
the
following
Turtle:
</p>
<del class="diff-old">@prefix xsd: &lt;http://www.w3.org/2001/XMLSchema#&gt; .

[ foaf:name &quot;John Smith&quot;;
  foaf:age  &quot;41&quot;^^xsd:integer;
  foaf:homepage ( &lt;http://personal.example.org/&gt; &lt;http://work.example.com/jsmith/&gt; )
</del>
<pre class="example">@prefix xsd: &lt;http://www.w3.org/2001/XMLSchema#&gt; .
<ins class="diff-chg">[ foaf:name &quot;John Smith&quot;;
  foaf:age  &quot;41&quot;^^xsd:integer;
  foaf:homepage ( &lt;http://personal.example.org/&gt; &lt;http://work.example.com/jsmith/&gt; )
</ins>
]
.
</pre>
<p>
Terms
may
also
be
defined
using
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
IRIs
</a>
or
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>.
This
allows
coercion
rules
to
by
applied
to
keys
which
are
not
represented
as
a
simple
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>.
For
example:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ,
    &quot;&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;&quot;:
    {
      &quot;@type&quot;: &quot;@id&quot;
    }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;</span>,<ins class="diff-chg">
    &quot;<span class="diff">foaf:age</span>&quot;:
    {
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;<span class="diff">foaf:homepage</span>&quot;:
</ins>    <span class="diff">{<ins class="diff-chg">
      &quot;@type&quot;: &quot;@id&quot;
    }</span>
  },
  &quot;foaf:name&quot;: &quot;John Smith&quot;,
  &quot;foaf:age&quot;: <span class="diff">&quot;41&quot;</span>,
  &quot;foaf:homepage&quot;:
</ins>  <span class="diff">[<ins class="diff-chg">
    &quot;http://personal.example.org/&quot;,
    &quot;http://work.example.com/jsmith/&quot;
  ]</span>
</ins>
}
</pre>
<p>
In
this
<del class="diff-old">case,
</del>
<ins class="diff-chg">case
</ins>
the
<code>
@id
</code>
definition
is
optional,
but
if
it
does
exist,
the
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
treated
as
a
term
<ins class="diff-new">(not
a
</ins><code><ins class="diff-new">
prefix:suffix
</ins></code><ins class="diff-new">
construct)
</ins>
so
that
the
actual
definition
of
a
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
becomes
unnecessary.
</p>
<p class="note">
Keys
in
the
context
are
treated
as
<a class="tref internalDFN" title="term" href="#dfn-term">
terms
</a>
for
the
purpose
of
expansion
and
value
coercion.
<del class="diff-old">This
allows
</del>
<ins class="diff-chg">At
times,
this
may
result
in
</ins>
multiple
representations
for
the
same
expanded
<abbr title="Internationalized Resource Identifier">
IRI
<del class="diff-old">,
which
may
</del>
</abbr>.
<ins class="diff-chg">For
example,
one
could
specify
that
</ins><code><ins class="diff-chg">
dog
</ins></code><ins class="diff-chg">
and
</ins><code><ins class="diff-chg">
cat
</ins></code><ins class="diff-chg">
both
expanded
to
</ins><code><ins class="diff-chg">
http://example.com/vocab#animal
</ins></code>.<ins class="diff-chg">
Doing
this
could
</ins>
be
useful
for
establishing
different
type
coercion
<ins class="diff-new">or
language
specification
</ins>
rules.
It
also
allows
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
(or
even
an
absolute
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
)
to
be
defined
as
something
else
<del class="diff-old">entirely,
</del>
<ins class="diff-chg">entirely.
For
example,
one
could
specify
that
the
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a><code><ins class="diff-chg">
http://example.org/zoo
</ins></code><ins class="diff-chg">
should
expand
to
</ins><code><ins class="diff-chg">
http://example.org/river
</ins></code>,
but
this
usage
is
<del class="diff-old">discouraged.
</del>
<ins class="diff-chg">discouraged
because
it
would
lead
to
a
great
deal
of
confusion
among
developers
attempting
to
understand
the
JSON-LD
document.
</ins>
</p>
<p>
Type
coercion
is
performed
using
the
unexpanded
value
of
the
key,
which
<em class="rfc2119" title="must">
must
</em>
<del class="diff-old">exactly
</del>
<ins class="diff-chg">have
an
exact
</ins>
match
<del class="diff-old">a
coercion
rule
</del>
<ins class="diff-chg">for
an
entry
</ins>
in
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>.
</p>
</div>
<div id="iri-expansion-within-a-context" typeof="bibo:Chapter" resource="#iri-expansion-within-a-context" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.7
</span>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
Expansion
Within
a
Context
</h3>
<p>
<del class="diff-old">To
be
consistent
with
JSON-LD,
in
</del>
<ins class="diff-chg">In
</ins>
general,
<del class="diff-old">anywhere
an
IRI
is
expected,
</del>
normal
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
expansion
rules
apply
<ins class="diff-new">anywhere
an
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr><ins class="diff-new">
is
expected
</ins>
(see
<a href="#iris">
IRIs
</a>
).
Within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition,
this
can
mean
that
terms
defined
within
<del class="diff-old">a
given
</del>
<ins class="diff-chg">the
</ins>
context
<em class="rfc2119" title="may">
may
</em>
also
be
used
within
that
<del class="diff-old">context,
</del>
<ins class="diff-chg">context
</ins>
as
long
as
there
are
no
circular
dependencies.
For
example,
it
is
common
to
use
the
<code>
xsd
</code>
namespace
when
defining
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>
s:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ,
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;: 
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;</span>,<ins class="diff-chg">
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;: <span class="diff">&quot;xsd:integer&quot;</span>
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</ins>
}
</pre>
<p>
In
this
example,
the
<code>
xsd
</code>
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
is
<del class="diff-old">defined,
</del>
<ins class="diff-chg">defined
</ins>
and
used
as
a
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
for
the
<code>
@type
</code>
coercion
of
the
<code>
age
</code>
property.
</p>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
<em class="rfc2119" title="may">
may
</em>
also
be
used
when
defining
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
of
another
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: ,
    &quot;age&quot;:
    {
      &quot;@id&quot;: ,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: ,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;</span>,<ins class="diff-chg">
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: <span class="diff">&quot;foaf:name&quot;</span>,
    &quot;age&quot;:
    {
      &quot;@id&quot;: <span class="diff">&quot;foaf:age&quot;</span>,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: <span class="diff">&quot;foaf:homepage&quot;</span>,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</ins>
}
</pre>
<p>
<del class="diff-old">Not
only
term
s,
but
also
</del>
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
Compact
IRIs
</a>
and
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>
<em class="rfc2119" title="may">
may
</em>
be
used
on
the
left-hand
side
of
a
<a class="tref internalDFN" title="term" href="#dfn-term">
<ins class="diff-new">term
</ins></a>
definition.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;&quot;:
    {
      &quot;@id&quot;: &quot;foaf:age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;&quot;:
    {
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;</span>,<ins class="diff-chg">
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;<span class="diff">foaf:age</span>&quot;:
    {
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;<span class="diff">foaf:homepage</span>&quot;:
</ins>    <span class="diff">{<ins class="diff-chg">
      &quot;@type&quot;: &quot;@id&quot;
    }</span>
  },
  ...
</ins>
}
</pre>
<p>
In
this
example,
the
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
form
is
used
in
two
different
ways.
<del class="diff-old">The
</del>
<ins class="diff-chg">In
the
</ins>
first
<del class="diff-old">way,
as
shown
with
</del>
<ins class="diff-chg">approach,
</ins>
<code>
foaf:age
</code>
declares
both
the
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
for
the
term
(using
short-form)
as
well
as
the
<code>
@type
</code>
associated
with
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>.
<del class="diff-old">The
</del>
<ins class="diff-chg">In
the
</ins>
second
<del class="diff-old">way,
</del>
<ins class="diff-chg">approach,
</ins>
only
<del class="diff-old">declares
</del>
the
<code>
@type
</code>
associated
with
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
<del class="diff-old">.
In
the
second
case,
the
</del>
</a>
<ins class="diff-chg">is
specified.
The
</ins>
JSON-LD
processor
will
<del class="diff-old">still
</del>
derive
the
full
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<ins class="diff-new">for
</ins><code><ins class="diff-new">
foaf:homepage
</ins></code>
by
looking
up
the
<code>
foaf
</code>
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
<del class="diff-old">for
foaf:homepage
.
</del>
</a>.
</p>
<p>
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
Absolute
IRIs
</a>
<em class="rfc2119" title="may">
may
</em>
also
be
used
<del class="diff-old">on
</del>
<ins class="diff-chg">in
</ins>
the
<del class="diff-old">left-hand
side
of
</del>
<ins class="diff-chg">key
position
in
</ins>
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;foaf:age&quot;:
    {
      &quot;@id&quot;: &quot;foaf:age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;&quot;:
    {
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;foaf:age&quot;:
    {
      &quot;@id&quot;: &quot;foaf:age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>&quot;:
    {
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</ins>
}
</pre>
<p>
In
order
for
the
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
to
match
above,
the
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<em class="rfc2119" title="must">
must
</em>
also
be
used
in
the
JSON-LD
document.
Also
note
that
<code>
foaf:homepage
</code>
will
not
use
the
<code>
{
&quot;@type&quot;:
&quot;@id&quot;
}
</code>
declaration
because
<code>
foaf:homepage
</code>
is
not
the
same
as
<code>
http://xmlns.com/foaf/0.1/homepage
</code>.
That
is,
a
JSON-LD
processor
will
use
direct
string
comparison
when
looking
up
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
in
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
before
it
applies
the
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
lookup
mechanism.
</p>
<p>
The
only
exception
for
using
terms
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
is
that
they
<em class="rfc2119" title="must not">
must
not
</em>
be
used
in
a
circular
manner.
That
is,
a
definition
of
<em>
term-1
</em>
<em class="rfc2119" title="must not">
must
not
</em>
depend
on
the
definition
of
<em>
term-2
</em>
if
<em>
term-2
</em>
also
depends
on
<em>
term-1
</em>.
For
example,
the
following
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition
is
illegal:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;term1&quot;: &quot;term2:foo&quot;,
    &quot;term2&quot;: &quot;term1:bar&quot;
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;term1&quot;: &quot;term2:foo&quot;,<ins class="diff-chg">
    &quot;term2&quot;: &quot;term1:bar&quot;</span>
  },
  ...
</ins>
}
</pre>
</div>
<div id="embedding" typeof="bibo:Chapter" resource="#embedding" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.8
</span>
Embedding
</h3>
<p>
Object
<dfn title="embedding" id="dfn-embedding">
embedding
</dfn>
is
a
JSON-LD
feature
that
allows
an
author
to
use
the
definition
of
JSON-LD
objects
as
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
values.
This
is
a
commonly
used
mechanism
for
creating
a
parent-child
relationship
between
two
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
s.
</p>
<p>
The
example
shows
two
subjects
related
by
a
property
from
the
first
subject:
</p>
<del class="diff-old">  {
...
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;&quot;:
  {
    &quot;&quot;,
    &quot;&quot;,
  }
...
</del>
  <pre class="example">{
<ins class="diff-chg">...
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;<span class="diff">knows</span>&quot;:
  {
    &quot;<span class="diff">@type</span>&quot;: &quot;<span class="diff">Person</span>&quot;,
    &quot;<span class="diff">name</span>&quot;: &quot;<span class="diff">Gregg Kellogg</span>&quot;,
  }
...
</ins>
}
</pre>
<p>
An
object
definition,
like
the
one
used
above,
<em class="rfc2119" title="may">
may
</em>
be
used
<del class="diff-old">as
a
JSON
value
at
</del>
<ins class="diff-chg">in
</ins>
any
<del class="diff-old">point
</del>
<ins class="diff-chg">value
position
</ins>
in
<del class="diff-old">JSON-LD.
</del>
<ins class="diff-chg">the
body
of
a
JSON-LD
document.
</ins>
</p>
</div>
<div id="named-graphs" typeof="bibo:Chapter" resource="#named-graphs" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.9
</span>
Named
Graphs
</h3>
<p>
The
<code>
@graph
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
is
used
to
<del class="diff-old">identify
</del>
<ins class="diff-chg">express
</ins>
a
set
of
JSON-LD
<del class="diff-old">object
definitions
</del>
<a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition">
<ins class="diff-chg">subject
definition
</ins></a><ins class="diff-chg">
s
</ins>
that
may
not
be
directly
related
<ins class="diff-new">to
one
another
</ins>
through
a
<del class="diff-old">property,
or
</del>
<ins class="diff-chg">property.
The
mechanism
may
also
be
used
</ins>
where
<a class="tref internalDFN" title="embedding" href="#dfn-embedding">
embedding
</a>
is
not
<del class="diff-old">appropriate.
</del>
<ins class="diff-chg">desirable
to
the
application.
</ins>
For
example:
</p>
<del class="diff-old">  {
  &quot;@context&quot;: ...,
  &quot;&quot;:
  [
    {
      &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Manu Sporny&quot;,
      &quot;knows&quot; &quot;http://greggkellogg.net/foaf#me&quot;
    },
    {
      &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Gregg Kellogg&quot;,
      &quot;knows&quot; &quot;http://manu.sporny.org/i/public&quot;
    }
  ]
</del>
  <pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: ...,
  &quot;<span class="diff">@graph</span>&quot;:
  [
    {
      &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Manu Sporny&quot;,
      &quot;knows&quot;: &quot;http://greggkellogg.net/foaf#me&quot;
    },
    {
      &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Gregg Kellogg&quot;,
      &quot;knows&quot;: &quot;http://manu.sporny.org/i/public&quot;
    }
  ]
</ins>
}
</pre>
<p>
In
this
case,
embedding
doesn't
work
as
each
JSON-LD
object
references
the
other.
Using
the
<code>
@graph
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
allows
multiple
resources
to
be
defined
within
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>,
and
allows
the
use
of
a
shared
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
This
is
equivalent
to
using
multiple
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
definitions
in
array
and
defining
the
<code>
@context
</code>
within
each
object:
</p>
<del class="diff-old">  
  {
    
    &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;name&quot;: &quot;Manu Sporny&quot;,
    &quot;knows&quot; &quot;http://greggkellogg.net/foaf#me&quot;
  },
  {
    
    &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;name&quot;: &quot;Gregg Kellogg&quot;,
    &quot;knows&quot; &quot;http://manu.sporny.org/i/public&quot;
  }
</del>
  <pre class="example"><span class="diff">[</span>
<ins class="diff-chg">  {
</ins>    <span class="diff">&quot;@context&quot;: ...,</span><ins class="diff-chg">
    &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;name&quot;: &quot;Manu Sporny&quot;,
    &quot;knows&quot;: &quot;http://greggkellogg.net/foaf#me&quot;
  },
  {
</ins>    <span class="diff">&quot;@context&quot;: ...,</span><ins class="diff-chg">
    &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;name&quot;: &quot;Gregg Kellogg&quot;,
    &quot;knows&quot;: &quot;http://manu.sporny.org/i/public&quot;
  }
</ins>
<span class="diff">
]
</span>
</pre>
<p>
<del class="diff-old">The
@graph
keyword
takes
on
additional
meaning
when
it
is
used
along
with
other
properties,
or
is
used
within
an
embedded
</del>
JSON-LD
<del class="diff-old">object.
In
this
case,
the
set
of
subject
definitions
,
or
subject
references
contained
within
a
@graph
is
given
a
</del>
<ins class="diff-chg">allows
you
to
</ins>
<em>
name
<del class="diff-old">,
based
</del>
</em>
<ins class="diff-chg">things
</ins>
on
the
<del class="diff-old">label
of
the
JSON-LD
object
containing
a
</del>
<ins class="diff-chg">Web
by
assigning
an
</ins>
<code>
<del class="diff-old">@graph
</del>
<ins class="diff-chg">@id
</ins>
</code>
<del class="diff-old">property,
either
</del>
<ins class="diff-chg">to
them,
which
is
typically
</ins>
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<del class="diff-old">,
or
</del>
</a>.
<ins class="diff-chg">This
notion
extends
to
the
ability
to
identify
graphs
in
the
same
manner.
A
developer
may
name
data
expressed
using
the
</ins><code><ins class="diff-chg">
@graph
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a><ins class="diff-chg">
by
pairing
it
with
</ins>
an
<del class="diff-old">unlabeled
node
</del>
<code>
<ins class="diff-chg">@id
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins>
</a>.
This
<del class="diff-old">allows
statements
</del>
<ins class="diff-chg">enables
the
developer
</ins>
to
<del class="diff-old">be
made
</del>
<ins class="diff-chg">make
statements
</ins>
about
<del class="diff-old">an
entire
</del>
<ins class="diff-chg">the
</ins>
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
<del class="diff-old">,
</del>
</a>
<ins class="diff-chg">itself,
</ins>
rather
than
just
a
single
JSON-LD
object.
</p>
<del class="diff-old">  {
  &quot;@context&quot;: ...,
  &quot;@id&quot;: &quot;http://example.org/linked-data-graph&quot;,
  &quot;asOf&quot;: { &quot;@value&quot;: &quot;2012-04-09&quot;, &quot;@type&quot;: &quot;xsd:date&quot; },
  &quot;@graph&quot;:
  [
    {
      &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Manu Sporny&quot;,
      &quot;knows&quot; &quot;http://greggkellogg.net/foaf#me&quot;
    },
    {
      &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Gregg Kellogg&quot;,
      &quot;knows&quot; &quot;http://manu.sporny.org/i/public&quot;
    },
    &quot;http://www.markus-lanthaler.com/&quot;
  ]
</del>
  <pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: ...,
</ins>  <span class="diff">&quot;@id&quot;: &quot;http://example.org/graphs/73&quot;,<ins class="diff-chg">
  &quot;asOf&quot;: { &quot;@value&quot;: &quot;2012-04-09&quot;, &quot;@type&quot;: &quot;xsd:date&quot; },
  &quot;@graph&quot;:</span>
  [
    {
      &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Manu Sporny&quot;,
      &quot;knows&quot;: &quot;http://greggkellogg.net/foaf#me&quot;
    },
    {
      &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Gregg Kellogg&quot;,
      &quot;knows&quot;: &quot;http://manu.sporny.org/i/public&quot;
    },
    &quot;http://www.markus-lanthaler.com/&quot;
  ]
</ins>
}
</pre>
<p>
<del class="diff-old">This
</del>
<ins class="diff-chg">The
</ins>
example
<del class="diff-old">says
that
there
is
</del>
<ins class="diff-chg">above
expresses
</ins>
a
<em>
<ins class="diff-new">named
</ins></em>
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
<ins class="diff-new">that
is
</ins>
identified
by
<ins class="diff-new">the
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>
<code>
<del class="diff-old">http://example.org/linked-data-graph
which
</del>
<ins class="diff-chg">http://example.org/graphs/73
</ins></code>.<ins class="diff-chg">
That
graph
</ins>
is
composed
of
the
statements
about
Manu
and
Gregg
and
a
reference
to
another
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
which
could
make
statements
about
Markus.
<del class="diff-old">Additionally,
there
is
information
</del>
<ins class="diff-chg">Meta-data
</ins>
about
the
graph
<del class="diff-old">itself,
which
indicates
a
time
at
</del>
<ins class="diff-chg">itself
is
also
expressed
via
the
</ins><code><ins class="diff-chg">
asOf
</ins></code><ins class="diff-chg">
property,
</ins>
which
<del class="diff-old">this
</del>
<ins class="diff-chg">specifies
when
the
</ins>
information
<del class="diff-old">as
asserted
to
be
true.
</del>
<ins class="diff-chg">was
retrieved
from
the
Web.
</ins>
</p>
</div>
<div id="identifying-unlabeled-nodes" typeof="bibo:Chapter" resource="#identifying-unlabeled-nodes" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.10
</span>
Identifying
Unlabeled
Nodes
</h3>
<p>
At
times,
it
becomes
necessary
to
be
able
to
express
information
without
being
able
to
specify
the
subject.
Typically,
this
type
of
node
is
called
an
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>
or
a
blank
node.
In
JSON-LD,
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>
identifiers
are
automatically
created
if
a
subject
is
not
specified
using
the
<code>
@id
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>.
However,
authors
may
provide
identifiers
for
unlabeled
nodes
by
using
the
special
<code>
_
</code>
(underscore)
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>.
This
allows
<ins class="diff-new">one
</ins>
to
reference
the
node
locally
within
the
<del class="diff-old">document
</del>
<ins class="diff-chg">document,
</ins>
but
<del class="diff-old">not
in
</del>
<ins class="diff-chg">makes
it
impossible
to
reference
the
node
from
</ins>
an
external
document.
<ins class="diff-new">The
</ins><a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node"><ins class="diff-new">
unlabeled
node
</ins></a><ins class="diff-new">
identifier
is
scoped
to
the
document
in
which
it
is
used.
</ins>
</p>
<del class="diff-old">{
...
  &quot;@id&quot;: &quot;&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;<span class="diff">_:foo</span>&quot;,
...
</ins>
}
</pre>
<p>
The
example
above
would
set
the
subject
to
<code>
_:foo
</code>,
which
can
then
be
used
<del class="diff-old">later
on
</del>
<ins class="diff-chg">elsewhere
</ins>
in
the
JSON-LD
<del class="diff-old">markup
</del>
<ins class="diff-chg">document
</ins>
to
refer
back
to
the
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>.
This
<del class="diff-old">practice,
however,
</del>
<ins class="diff-chg">practice
</ins>
is
<del class="diff-old">usually
</del>
frowned
upon
when
generating
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
If
a
developer
finds
that
they
refer
to
the
unlabeled
node
more
than
once,
they
should
consider
naming
the
node
using
a
de-referenceable
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
</div>
<div id="aliasing-keywords" typeof="bibo:Chapter" resource="#aliasing-keywords" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.11
</span>
Aliasing
Keywords
</h3>
<p>
<del class="diff-old">JSON-LD
allows
all
</del>
<ins class="diff-chg">Each
</ins>
of
the
<del class="diff-old">syntax
</del>
<ins class="diff-chg">JSON-LD
</ins>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>,
except
for
<code>
@context
</code>,
<del class="diff-old">to
</del>
<em class="rfc2119" title="may">
<ins class="diff-chg">may
</ins></em>
be
<del class="diff-old">aliased.
</del>
<ins class="diff-chg">aliased
to
application-specific
keywords.
</ins>
This
feature
allows
<del class="diff-old">more
</del>
legacy
JSON
content
to
be
<del class="diff-old">supported
</del>
<ins class="diff-chg">utilized
</ins>
by
<del class="diff-old">JSON-LD.
It
</del>
<ins class="diff-chg">JSON-LD
by
re-using
JSON
keys
that
already
exist
in
legacy
documents.
This
feature
</ins>
also
allows
developers
to
design
domain-specific
implementations
using
only
the
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
     ,
     ,
     &quot;name&quot;: &quot;http://schema.org/name&quot;
  },
  &quot;url&quot;: &quot;http://example.com/about#gregg&quot;,
  &quot;a&quot;: &quot;http://schema.org/Person&quot;,
  &quot;name&quot;: &quot;Gregg Kellogg&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>     <span class="diff">&quot;url&quot;: &quot;@id&quot;</span>,     <span class="diff">&quot;a&quot;: &quot;@type&quot;</span>,<ins class="diff-chg">
     &quot;name&quot;: &quot;http://schema.org/name&quot;
  },
  &quot;<span class="diff">url</span>&quot;: &quot;http://example.com/about#gregg&quot;,
  &quot;<span class="diff">a</span>&quot;: &quot;http://schema.org/Person&quot;,
  &quot;name&quot;: &quot;Gregg Kellogg&quot;
</ins>
}
</pre>
<p>
In
the
example
above,
the
<code>
@id
</code>
and
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>
have
been
given
the
aliases
<strong>
url
</strong>
and
<strong>
a
</strong>,
respectively.
</p>
</div>
<div id="expanded-document-form" typeof="bibo:Chapter" resource="#expanded-document-form" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.12
</span>
<del class="diff-old">Expansion
</del>
<ins class="diff-chg">Expanded
Document
Form
</ins>
</h3>
<p>
The
JSON-LD
API
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
]
defines
an
method
for
<em>
expanding
</em>
a
JSON-LD
document.
Expansion
is
the
process
of
taking
a
JSON-LD
document
and
applying
a
<del class="diff-old">context
</del>
<code>
<ins class="diff-chg">@context
</ins></code>
such
that
all
IRIs,
datatypes,
and
<del class="diff-old">literal
</del>
values
are
expanded
so
that
the
<del class="diff-old">context
</del>
<code>
<ins class="diff-chg">@context
</ins></code>
is
no
longer
necessary.
<del class="diff-old">JSON-LD
document
expansion
is
typically
used
as
a
part
of
Framing
.
</del>
</p>
<p>
For
example,
assume
the
following
JSON-LD
input
document:
</p>
<del class="diff-old">{
   &quot;@context&quot;:
   {
      &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
      &quot;homepage&quot;: {
        &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
        &quot;@type&quot;, &quot;@id&quot;
      }
   },
   &quot;name&quot;: &quot;Manu Sporny&quot;,
   &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
</del>
<pre class="example">{
<ins class="diff-chg">   &quot;@context&quot;:
   {
      &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
      &quot;homepage&quot;: {
        &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
        &quot;@type&quot;, &quot;@id&quot;
      }
   },
   &quot;name&quot;: &quot;Manu Sporny&quot;,
   &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
</ins>
}
</pre>
<p>
Running
the
JSON-LD
Expansion
algorithm
against
the
JSON-LD
input
document
provided
above
would
result
in
the
following
output:
</p>
<del class="diff-old">[
  {
    &quot;http://xmlns.com/foaf/0.1/name&quot;: [ &quot;Manu Sporny&quot; ],
    &quot;http://xmlns.com/foaf/0.1/homepage&quot;: [
      {
       &quot;@id&quot;: &quot;http://manu.sporny.org/&quot;
      }
    ]
  }
</del>
<pre class="example">[
<ins class="diff-chg">  {
    &quot;http://xmlns.com/foaf/0.1/name&quot;: [
      { &quot;@value&quot;: &quot;Manu Sporny&quot; }
    ],
    &quot;http://xmlns.com/foaf/0.1/homepage&quot;: [
      { &quot;@id&quot;: &quot;http://manu.sporny.org/&quot; }
    ]
  }
</ins>
]
</pre>
<p>
<ins class="diff-new">Expanded
document
form
is
useful
when
an
application
has
to
process
input
data
in
a
deterministic
form.
It
has
been
optimized
to
ensure
that
the
code
that
developers
have
to
write
is
minimized
compared
to
the
code
that
would
have
to
be
written
to
operate
on
</ins><a href="#compact-document-form"><ins class="diff-new">
compact
document
form
</ins></a>.</p>
</div>
<div id="compact-document-form" typeof="bibo:Chapter" resource="#compact-document-form" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
4.13
</span>
<del class="diff-old">Compaction
</del>
<ins class="diff-chg">Compact
Document
Form
</ins>
</h3>
<p>
The
JSON-LD
API
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
]
defines
a
method
for
<em>
compacting
</em>
a
JSON-LD
document.
Compaction
is
the
process
of
taking
a
JSON-LD
document
and
applying
a
context
such
that
the
most
compact
form
of
the
document
is
generated.
JSON
is
typically
expressed
in
a
very
compact,
key-value
format.
That
is,
full
IRIs
are
rarely
used
as
keys.
At
times,
a
JSON-LD
document
may
be
received
that
is
not
in
its
most
compact
form.
JSON-LD,
via
the
API,
provides
a
way
to
compact
a
JSON-LD
document.
</p>
<p>
For
example,
assume
the
following
JSON-LD
input
document:
</p>
<del class="diff-old">[
  {
    &quot;http://xmlns.com/foaf/0.1/name&quot;: [ &quot;Manu Sporny&quot; ],
    &quot;http://xmlns.com/foaf/0.1/homepage&quot;: [
      {
       &quot;@id&quot;: &quot;http://manu.sporny.org/&quot;
      }
    ]
  }
</del>
<pre class="example">[
<ins class="diff-chg">  {
    &quot;http://xmlns.com/foaf/0.1/name&quot;: [ &quot;Manu Sporny&quot; ],
    &quot;http://xmlns.com/foaf/0.1/homepage&quot;: [
      {
       &quot;@id&quot;: &quot;http://manu.sporny.org/&quot;
      }
    ]
  }
</ins>
]
</pre>
<p>
Additionally,
assume
the
following
developer-supplied
JSON-LD
context:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  }
</ins>
}
</pre>
<p>
Running
the
JSON-LD
Compaction
algorithm
given
the
context
supplied
above
against
the
JSON-LD
input
document
provided
above
would
result
in
the
following
output:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
</ins>
}
</pre>
<p>
The
compaction
algorithm
<del class="diff-old">also
</del>
enables
<del class="diff-old">the
</del>
<ins class="diff-chg">a
</ins>
developer
to
map
any
<del class="diff-old">expanded
format
</del>
<ins class="diff-chg">document
</ins>
into
an
application-specific
compacted
<del class="diff-old">format.
</del>
<ins class="diff-chg">form
by
first
</ins><a href="#expanded-document-form"><ins class="diff-chg">
expanding
the
document
</ins></a>.
While
the
context
provided
above
mapped
<code>
http://xmlns.com/foaf/0.1/name
</code>
to
<strong>
name
</strong>,
it
could
have
also
mapped
it
to
any
arbitrary
string
provided
by
the
developer.
<ins class="diff-new">This
powerful
mechanism,
along
with
another
JSON-LD
API
technique
called
</ins><em><ins class="diff-new">
framing
</ins></em>,<ins class="diff-new">
allows
the
developer
to
re-shape
the
incoming
JSON
data
into
a
format
that
is
optimized
for
their
application.
</ins>
</p>
</div>
</div>
<div class="appendix normative section" id="json-ld-grammar" typeof="bibo:Chapter" resource="#json-ld-grammar" rel="bibo:chapter">
<h2>
<span class="secno">
<del class="diff-old">4.14
</del>
<ins class="diff-chg">A.
</ins>
</span>
<del class="diff-old">Framing
</del>
<ins class="diff-chg">JSON-LD
Grammar
</ins></h2>
<p>
<del class="diff-old">The
</del>
<ins class="diff-chg">Since
the
</ins>
JSON-LD
<del class="diff-old">API
[
JSON-LD-API
]
defines
an
method
for
framing
</del>
<ins class="diff-chg">syntax
is
</ins>
a
<ins class="diff-new">subset
of
the
JSON
syntax,
it
follows
that
all
well-formed
</ins>
JSON-LD
<del class="diff-old">document.
This
allows
developers
to
query
by
example
and
force
</del>
<ins class="diff-chg">documents
are
well-formed
JSON
documents.
It
also
means
that
</ins>
a
<del class="diff-old">specific
tree
layout
to
</del>
<ins class="diff-chg">non-well-formed
JSON
document
can
never
be
</ins>
a
<ins class="diff-new">well-formed
</ins>
JSON-LD
document.
<del class="diff-old">A
</del>
<ins class="diff-chg">Furthermore,
</ins>
JSON-LD
<del class="diff-old">document
is
</del>
<ins class="diff-chg">places
</ins>
a
<del class="diff-old">representation
</del>
<ins class="diff-chg">number
</ins>
of
<del class="diff-old">a
directed
graph.
A
single
directed
graph
can
have
many
different
serializations,
each
expressing
exactly
</del>
<ins class="diff-chg">restrictions
on
</ins>
the
<del class="diff-old">same
information.
Developers
typically
work
with
trees,
represented
as
</del>
JSON
<del class="diff-old">object
s.
While
mapping
</del>
<ins class="diff-chg">syntax
in
order
to
define
</ins>
a
<del class="diff-old">graph
</del>
<em>
<ins class="diff-chg">grammar
</ins></em><ins class="diff-chg">
that
is
used
</ins>
to
<ins class="diff-new">express
valid
JSON-LD
documents.
At
times,
even
if
this
grammar
is
violated,
</ins>
a
<del class="diff-old">tree
can
be
done,
</del>
<ins class="diff-chg">JSON-LD
processor
will
do
its
best
to
recover
from
</ins>
the
<del class="diff-old">layout
</del>
<ins class="diff-chg">error
and
deterministically
transform
the
author's
markup
into
valid
JSON-LD.
</ins></p><p class="issue"><ins class="diff-chg">
The
final
nuanced
details
</ins>
of
the
<del class="diff-old">end
result
must
be
specified
</del>
<ins class="diff-chg">exact
grammar
are
still
being
discussed,
as
well
as
the
best
mechanism
to
express
these
restrictions.
EBNF
seems
like
overkill
since
it's
a
subset
of
JSON.
EBNF
doesn't
quite
capture
some
of
the
more
esoteric
restrictions
</ins>
in
<del class="diff-old">advance.
</del>
<ins class="diff-chg">the
language.
</ins></p><ol><li>
A
<del class="diff-old">Frame
can
be
used
by
a
developer
on
a
</del>
JSON-LD
document
<del class="diff-old">to
specify
a
deterministic
layout
for
a
graph.
Framing
</del>
is
<del class="diff-old">the
process
</del>
<ins class="diff-chg">composed
</ins>
of
<del class="diff-old">taking
a
JSON-LD
document,
which
expresses
</del>
a
<del class="diff-old">graph
</del>
<ins class="diff-chg">single
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
or
an
array
</ins>
of
<del class="diff-old">information,
and
applying
a
specific
graph
layout
(called
a
Frame
</del>
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
<ins class="diff-chg">JSON
object
</ins>
</a>
<del class="diff-old">).
</del>
<ins class="diff-chg">s.
</ins></li><li>
The
<del class="diff-old">JSON-LD
document
below
expresses
</del>
<ins class="diff-chg">value
of
</ins><code><ins class="diff-chg">
@id
</ins></code><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
</ins><code><ins class="diff-chg">
null
</ins></code>,
a
<del class="diff-old">library,
</del>
<a class="tref internalDFN" title="term" href="#dfn-term">
<ins class="diff-chg">term
</ins></a>,
a
<del class="diff-old">book
</del>
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
<ins class="diff-chg">compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a>,<ins class="diff-chg">
or
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a>.</li><li><ins class="diff-chg">
A
</ins><code><ins class="diff-chg">
@id
</ins></code><ins class="diff-chg">
keyword
</ins>
and
a
<del class="diff-old">chapter:
{
  &quot;@context&quot;: {
    &quot;Book&quot;:         &quot;http://example.org/vocab#Book&quot;,
    &quot;Chapter&quot;:      &quot;http://example.org/vocab#Chapter&quot;,
    &quot;contains&quot;:     {
      &quot;@id&quot;: &quot;http://example.org/vocab#contains&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;creator&quot;:      &quot;http://purl.org/dc/terms/creator&quot;,
    &quot;description&quot;:  &quot;http://purl.org/dc/terms/description&quot;,
    &quot;Library&quot;:      &quot;http://example.org/vocab#Library&quot;,
    &quot;title&quot;:        &quot;http://purl.org/dc/terms/title&quot;
  },
  &quot;@graph&quot;:
  [{
    &quot;@id&quot;: &quot;http://example.com/library&quot;,
    &quot;@type&quot;: &quot;Library&quot;,
    &quot;contains&quot;: &quot;http://example.org/library/the-republic&quot;
  },
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,
    &quot;@type&quot;: &quot;Book&quot;,
    &quot;creator&quot;: &quot;Plato&quot;,
    &quot;title&quot;: &quot;The Republic&quot;,
    &quot;contains&quot;: &quot;http://example.org/library/the-republic#introduction&quot;
  },
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,
    &quot;@type&quot;: &quot;Chapter&quot;,
    &quot;description&quot;: &quot;An introductory chapter on The Republic.&quot;,
    &quot;title&quot;: &quot;The Introduction&quot;
  }]
}
Developers
typically
like
to
operate
on
items
</del>
<code>
<ins class="diff-chg">@language
</ins></code><ins class="diff-chg">
keyword
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
exist
</ins>
in
<ins class="diff-new">the
same
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a>.</li><li><ins class="diff-new">
A
</ins><code><ins class="diff-new">
@id
</ins></code><ins class="diff-new">
keyword
and
</ins>
a
<del class="diff-old">hierarchical,
tree-based
fashion.
Ideally,
</del>
<code>
<ins class="diff-chg">@container
</ins></code><ins class="diff-chg">
keyword
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
exist
in
the
same
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a>.</li><li><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><em class="rfc2119" title="may"><ins class="diff-chg">
may
</ins></em><ins class="diff-chg">
contain
</ins>
a
<del class="diff-old">developer
would
want
</del>
<code>
<ins class="diff-chg">@context
</ins></code><ins class="diff-chg">
property.
</ins></li><li><ins class="diff-chg">
A
</ins><code><ins class="diff-chg">
@context
</ins></code><ins class="diff-chg">
value
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
contain
an
embedded
</ins><code><ins class="diff-chg">
@context
</ins></code><ins class="diff-chg">
definition.
</ins></li><li><ins class="diff-chg">
The
value
associated
with
</ins>
the
<del class="diff-old">data
above
sorted
into
top-level
libraries,
then
</del>
<code>
<ins class="diff-chg">@context
</ins></code><ins class="diff-chg">
keyword
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a>,<ins class="diff-chg">
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a>,<ins class="diff-chg">
null,
or
an
array
containing
a
combination
of
</ins>
the
<del class="diff-old">books
that
are
contained
in
each
library,
and
then
</del>
<ins class="diff-chg">allowed
values.
</ins></li><li><ins class="diff-chg">
The
value
associated
with
</ins>
the
<del class="diff-old">chapters
contained
</del>
<ins class="diff-chg">keys
used
</ins>
in
<ins class="diff-new">a
</ins><code><ins class="diff-new">
@context
</ins></code><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
be
a
</ins><code><ins class="diff-new">
null
</ins></code>,<ins class="diff-new">
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>,<ins class="diff-new">
or
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a>.</li><li><ins class="diff-new">
For
</ins>
each
<del class="diff-old">book.
To
achieve
</del>
<ins class="diff-chg">value
</ins>
that
<del class="diff-old">layout,
the
developer
can
define
the
following
frame
:
{
  &quot;@context&quot;: {
    &quot;Book&quot;:         &quot;http://example.org/vocab#Book&quot;,
    &quot;Chapter&quot;:      &quot;http://example.org/vocab#Chapter&quot;,
    &quot;contains&quot;:     &quot;http://example.org/vocab#contains&quot;,
    &quot;creator&quot;:      &quot;http://purl.org/dc/terms/creator&quot;,
    &quot;description&quot;:  &quot;http://purl.org/dc/terms/description&quot;,
    &quot;Library&quot;:      &quot;http://example.org/vocab#Library&quot;,
    &quot;title&quot;:        &quot;http://purl.org/dc/terms/title&quot;
  },
  &quot;@type&quot;: &quot;Library&quot;,
  &quot;contains&quot;: {
    &quot;@type&quot;: &quot;Book&quot;,
    &quot;contains&quot;: {
      &quot;@type&quot;: &quot;Chapter&quot;
    }
  }
}
When
the
framing
algorithm
</del>
is
<del class="diff-old">run
against
the
previously
defined
JSON-LD
document,
paired
with
the
frame
</del>
<ins class="diff-chg">a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins>
</a>
<del class="diff-old">above,
the
following
JSON-LD
document
</del>
<ins class="diff-chg">that
</ins>
is
<del class="diff-old">the
end
result:
{
  &quot;@context&quot;: {
    &quot;Book&quot;:         &quot;http://example.org/vocab#Book&quot;,
    &quot;Chapter&quot;:      &quot;http://example.org/vocab#Chapter&quot;,
    &quot;contains&quot;:     &quot;http://example.org/vocab#contains&quot;,
    &quot;creator&quot;:      &quot;http://purl.org/dc/terms/creator&quot;
    &quot;description&quot;:  &quot;http://purl.org/dc/terms/description&quot;
    &quot;Library&quot;:      &quot;http://example.org/vocab#Library&quot;,
    &quot;title&quot;:        &quot;http://purl.org/dc/terms/title&quot;
  },
  &quot;@id&quot;: &quot;http://example.org/library&quot;,
  &quot;@type&quot;: &quot;Library&quot;,
  &quot;contains&quot;: {
    
    &quot;@type&quot;: &quot;Book&quot;,
    
    
    &quot;contains&quot;: {
      
      &quot;@type&quot;: &quot;Chapter&quot;,
      
      
    },
  },
}
</del>
<ins class="diff-chg">associated
with
a
key
in
a
</ins><code><ins class="diff-chg">
@context
</ins></code>:<ol><li><code><ins class="diff-chg">
@id
</ins></code><ins class="diff-chg">
and
</ins><code><ins class="diff-chg">
@type
</ins></code><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr>
<del class="diff-old">4.14.1
Framing
Operators
A
frame
</del>
</a>
<del class="diff-old">is
a
JSON-LD
document
</del>
<ins class="diff-chg">or
</ins><code><ins class="diff-chg">
null
</ins></code></li><li><code><ins class="diff-chg">
@container
</ins></code><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
associated
</ins>
with
<del class="diff-old">some
extra
syntactic
elements
used
to
match
against
parts
of
an
input
document.
These
operators
work
by
matching
on
elements
</del>
<ins class="diff-chg">a
value
</ins>
of
<del class="diff-old">subject
definitions
</del>
<ins class="diff-chg">either
</ins><code><ins class="diff-chg">
@set
</ins></code><ins class="diff-chg">
or
</ins><code><ins class="diff-chg">
@list
</ins></code>.</li><li><code><ins class="diff-chg">
@language
</ins></code><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
a
string
expressed
in
[
</ins><cite><a class="bibref" rel="biblioentry" href="#bib-BCP47"><ins class="diff-chg">
BCP47
</ins>
</a>
<del class="diff-old">comprising
the
document.
Type
Matching
</del>
</cite>
<ins class="diff-chg">]
or
</ins><code><ins class="diff-chg">
null
</ins></code>.</li><li><ins class="diff-chg">
Any
other
property
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
ignored
by
a
JSON-LD
processor
and
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
preserved
in
compaction
and
framing.
</ins></li></ol></li><li>
A
<del class="diff-old">frame
</del>
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
<ins class="diff-chg">JSON
object
</ins>
</a>
<del class="diff-old">including
a
</del>
<em class="rfc2119" title="may">
<ins class="diff-chg">may
</ins></em><ins class="diff-chg">
have
an
</ins>
<code>
<del class="diff-old">@type
</del>
<ins class="diff-chg">@graph
</ins>
</code>
<del class="diff-old">with
one
or
more
values
matches
any
subject
definition
having
</del>
<ins class="diff-chg">property.
</ins></li><li><ins class="diff-chg">
The
value
of
</ins>
a
<code>
<del class="diff-old">@type
</del>
<ins class="diff-chg">@graph
</ins>
</code>
property
<del class="diff-old">that
includes
the
specified
type.
Type
Wildcard
</del>
<em class="rfc2119" title="must">
<ins class="diff-chg">must
</ins></em><ins class="diff-chg">
be
null,
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
<ins class="diff-chg">IRI
</ins></abbr></a>,<ins class="diff-chg">
or
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a>.</li><li>
A
<del class="diff-old">frame
</del>
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
<ins class="diff-chg">JSON
object
</ins>
</a>
<del class="diff-old">including
</del>
<ins class="diff-chg">containing
</ins>
a
<code>
<del class="diff-old">@type
</del>
<ins class="diff-chg">@set
</ins>
</code>
<del class="diff-old">having
only
an
empty
</del>
<ins class="diff-chg">key
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
have
any
other
keys.
</ins></li><li><ins class="diff-chg">
A
</ins>
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
<del class="diff-old">matches
any
subject
definition
having
</del>
<ins class="diff-chg">containing
</ins>
a
<code>
<del class="diff-old">@type
</del>
<ins class="diff-chg">@list
</ins>
</code>
<del class="diff-old">property
with
</del>
<ins class="diff-chg">key
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
have
</ins>
any
<del class="diff-old">value.
Duck
Typing
A
frame
</del>
<ins class="diff-chg">other
keys.
</ins></li><li><ins class="diff-chg">
The
value
of
an
</ins><code><ins class="diff-chg">
@set
</ins></code><ins class="diff-chg">
or
</ins><code><ins class="diff-chg">
@list
</ins></code><ins class="diff-chg">
key
can
be
a
string,
a
number,
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a>,<ins class="diff-chg">
or
an
array
containing
a
combination
of
the
allowed
values.
</ins></li><li><ins class="diff-chg">
For
each
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins>
</a>
<del class="diff-old">without
</del>
<ins class="diff-chg">that
contains
</ins>
a
<code>
<ins class="diff-new">@value
</ins></code><ins class="diff-new">
key:
</ins><ol><li><ins class="diff-new">
It
</ins><em class="rfc2119" title="may"><ins class="diff-new">
may
</ins></em><ins class="diff-new">
have
a
</ins><code><ins class="diff-new">
@language
</ins></code><ins class="diff-new">
or
</ins><code>
@type
</code>
<del class="diff-old">definition
but
with
other
non-
keyword
</del>
property
<del class="diff-old">definitions
matches
</del>
<ins class="diff-chg">and
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
have
</ins>
any
<del class="diff-old">subject
definition
having
</del>
<ins class="diff-chg">other
properties.
</ins></li><li><ins class="diff-chg">
It
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
contain
both
the
</ins><code><ins class="diff-chg">
@language
</ins></code><ins class="diff-chg">
and
</ins><code><ins class="diff-chg">
@type
</ins></code><ins class="diff-chg">
keys
</ins>
at
<del class="diff-old">least
</del>
the
same
<del class="diff-old">set
</del>
<ins class="diff-chg">time.
</ins></li><li><ins class="diff-chg">
The
value
</ins>
of
<del class="diff-old">properties.
Embedding
A
frame
including
</del>
<ins class="diff-chg">the
</ins><code><ins class="diff-chg">
@value
</ins></code><ins class="diff-chg">
key
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
</ins>
a
<del class="diff-old">property
which
references
another
frame
causes
subject
definitions
containing
that
property
and
referencing
either
other
subject
definitions
</del>
<ins class="diff-chg">string
</ins>
or
<del class="diff-old">subject
references
to
embed
subject
definitions
matching
</del>
<ins class="diff-chg">a
number.
</ins></li><li><ins class="diff-chg">
The
value
of
</ins>
the
<del class="diff-old">embed
frame
to
</del>
<code>
<ins class="diff-chg">@language
</ins></code><ins class="diff-chg">
key
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em>
be
<del class="diff-old">defined
within
that
property.
Subject
references
that
don't
match
the
embed
frame
are
dropped.
The
</del>
<code>
<ins class="diff-chg">null
</ins></code><ins class="diff-chg">
or
a
string
in
</ins>
[
<cite>
<del class="diff-old">JSON-LD-API
</del>
<a class="bibref" rel="biblioentry" href="#bib-BCP47">
<ins class="diff-chg">BCP47
</ins>
</a>
</cite>
]
<del class="diff-old">describes
other
flags
and
keywords
that
are
used
</del>
<ins class="diff-chg">format.
</ins></li><li><ins class="diff-chg">
The
value
of
</ins><code><ins class="diff-chg">
@type
</ins></code><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
</ins><code><ins class="diff-chg">
null
</ins></code>,<ins class="diff-chg">
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a>,<ins class="diff-chg">
a
</ins><a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri"><ins class="diff-chg">
compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a>,<ins class="diff-chg">
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a>,<ins class="diff-chg">
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a>,<ins class="diff-chg">
or
an
array
containing
a
combination
of
the
allowed
values.
</ins></li></ol></li><li><ins class="diff-chg">
In
the
body
of
a
JSON-LD
document,
the
value
of
</ins><code><ins class="diff-chg">
@type
</ins></code><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
be
</ins><code><ins class="diff-chg">
@id
</ins></code>.<ins class="diff-chg">
This
is
in
contrast
</ins>
to
<del class="diff-old">gain
even
more
control
over
</del>
the
<del class="diff-old">framed
output.
</del>
<ins class="diff-chg">use
of
</ins><code><ins class="diff-chg">
@type
</ins></code><ins class="diff-chg">
in
the
</ins><code><ins class="diff-chg">
@context
</ins></code>,<ins class="diff-chg">
where
this
is
allowed.
</ins></li></ol>
</div>
<div class="appendix informative section" id="markup-examples" typeof="bibo:Chapter" resource="#markup-examples" rel="bibo:chapter">
<h2>
<span class="secno">
<del class="diff-old">A.
</del>
<ins class="diff-chg">B.
</ins>
</span>
Markup
Examples
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
JSON-LD
is
a
specification
for
representing
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
in
JSON.
A
common
way
of
working
with
Linked
Data
is
through
<dfn title="rdf" id="dfn-rdf">
RDF
</dfn>,
the
Resource
Description
Framework.
RDF
can
be
expressed
using
JSON-LD
by
associating
JSON-LD
concepts
such
as
<code>
@id
</code>
and
<code>
@type
</code>
with
the
equivalent
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
in
RDF.
Further
information
about
RDF
may
be
found
in
<ins class="diff-new">the
</ins>
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RDF-PRIMER">
RDF-PRIMER
</a>
</cite>
].
</p>
<p>
The
JSON-LD
markup
examples
below
demonstrate
how
JSON-LD
can
be
used
to
express
semantic
data
marked
up
in
other
languages
such
as
Turtle,
RDFa,
Microformats,
and
Microdata.
These
sections
are
merely
provided
as
proof
that
JSON-LD
is
very
flexible
in
what
it
can
express
across
different
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
approaches.
<del class="diff-old">Details
of
</del>
<ins class="diff-chg">Further
information
on
</ins>
transforming
JSON-LD
into
RDF
are
<del class="diff-old">defined
</del>
<ins class="diff-chg">detailed
</ins>
in
<ins class="diff-new">the
</ins>
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
].
</p>
<div id="turtle" typeof="bibo:Chapter" resource="#turtle" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
<del class="diff-old">A.1
</del>
<ins class="diff-chg">B.1
</ins>
</span>
Turtle
</h3>
<p>
The
following
are
examples
of
representing
<a class="tref internalDFN" title="rdf" href="#dfn-rdf">
RDF
</a>
as
expressed
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-TURTLE">
TURTLE
</a>
</cite>
]
into
JSON-LD.
</p>
<div id="prefix-definitions" typeof="bibo:Chapter" resource="#prefix-definitions" rel="bibo:chapter" class="section">
<h4>
<span class="secno">
<del class="diff-old">A.1.1
</del>
<ins class="diff-chg">B.1.1
</ins>
</span>
Prefix
definitions
</h4>
<p>
The
JSON-LD
context
has
direct
equivalents
for
the
Turtle
<code>
@prefix
</code>
declaration:
</p>
<del class="diff-old">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .

&lt;http://manu.sporny.org/i/public&gt; a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
</del>
<pre class="example">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
<ins class="diff-chg">&lt;http://manu.sporny.org/i/public&gt; a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
</ins>
foaf:homepage
&lt;http://manu.sporny.org/&gt;
.
</pre>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: &quot;http://manu.sporny.org/&quot; }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: &quot;http://manu.sporny.org/&quot; }
</ins>
}
</pre>
<div class="note">
<p>
JSON-LD
has
no
equivalent
for
the
Turtle
<code>
@base
</code>
declaration.
<del class="diff-old">Authors
could,
of
course,
</del>
<ins class="diff-chg">Instead,
authors
may
</ins>
use
a
prefix
definition
to
resolve
<a class="tref internalDFN" title="relative_iri" href="#dfn-relative_iri">
relative
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<del class="diff-old">s.
For
example,
an
empty
prefix
could
be
used
to
get
a
similar
effect
to
@base
:
</del>
<ins class="diff-chg">s:
</ins>
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: ,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;base&quot;: &quot;http://manu.sporny.org/&quot;,</span><ins class="diff-chg">
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: <span class="diff">&quot;base:i/public&quot;</span>,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: <span class="diff">&quot;base&quot; </span>}
</ins>
}
</pre>
</div>
</div>
<div id="embedding-1" typeof="bibo:Chapter" resource="#embedding-1" rel="bibo:chapter" class="section">
<h4>
<span class="secno">
<del class="diff-old">A.1.2
</del>
<ins class="diff-chg">B.1.2
</ins>
</span>
Embedding
</h4>
<p>
Both
Turtle
and
JSON-LD
allow
embedding
of
objects,
although
Turtle
only
allows
embedding
of
objects
which
use
unlabeled
node
identifiers.
</p>
</div>
<del class="diff-old">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .

&lt;http://manu.sporny.org/i/public&gt;
  a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
</del>
<pre class="example">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
<ins class="diff-chg">&lt;http://manu.sporny.org/i/public&gt;
  a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
</ins>
foaf:knows
[
a
foaf:Person;
foaf:name
&quot;Gregg
Kellogg&quot;
]
.
</pre>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:knows&quot;:
  {
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;foaf:name&quot;: &quot;Gregg Kellogg&quot;
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:knows&quot;:
  {
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;foaf:name&quot;: &quot;Gregg Kellogg&quot;
  }
</ins>
}
</pre>
<div id="lists" typeof="bibo:Chapter" resource="#lists" rel="bibo:chapter" class="section">
<h4>
<span class="secno">
<del class="diff-old">A.1.3
</del>
<ins class="diff-chg">B.1.3
</ins>
</span>
Lists
</h4>
<p>
Both
JSON-LD
and
Turtle
can
represent
sequential
lists
of
values.
</p>
<del class="diff-old">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .

&lt;http://example.org/people#joebob&gt; a foaf:Person;
  foaf:name &quot;Joe Bob&quot;;
</del>
<pre class="example">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
<ins class="diff-chg">&lt;http://example.org/people#joebob&gt; a foaf:Person;
  foaf:name &quot;Joe Bob&quot;;
</ins>
foaf:nick
(
&quot;joe&quot;
&quot;bob&quot;
&quot;jaybee&quot;
)
.
</pre>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Joe Bob&quot;,
  &quot;foaf:nick&quot;:
  {
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybe&quot; ]
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Joe Bob&quot;,
  &quot;foaf:nick&quot;:
  {
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]
  }
</ins>
}
</pre>
</div>
</div>
<div id="rdfa" typeof="bibo:Chapter" resource="#rdfa" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
<del class="diff-old">A.2
</del>
<ins class="diff-chg">B.2
</ins>
</span>
RDFa
</h3>
<p>
The
following
example
describes
three
people
with
their
respective
names
and
homepages.
</p>
<del class="diff-old">&gt;
   &lt;ul&gt;
      &lt;li &gt;
        &lt;a &gt;Bob&lt;/a&gt;
      &lt;/li&gt;
      &lt;li &gt;
        &lt;a &gt;Eve&lt;/a&gt;
      &lt;/li&gt;
      &lt;li &gt;
        &lt;a &gt;Manu&lt;/a&gt;
      &lt;/li&gt;
   &lt;/ul&gt;
</del>
<pre class="example">&lt;div <span class="diff">prefix=&quot;foaf: http://xmlns.com/foaf/0.1/&quot;</span>&gt;
<ins class="diff-chg">   &lt;ul&gt;
      &lt;li <span class="diff">typeof=&quot;foaf:Person&quot;</span>&gt;
        &lt;a <span class="diff">rel=&quot;foaf:homepage&quot; href=&quot;http://example.com/bob/&quot; property=&quot;foaf:name&quot; </span>&gt;Bob&lt;/a&gt;
      &lt;/li&gt;
      &lt;li <span class="diff">typeof=&quot;foaf:Person&quot;</span>&gt;
        &lt;a <span class="diff">rel=&quot;foaf:homepage&quot; href=&quot;http://example.com/eve/&quot; property=&quot;foaf:name&quot; </span>&gt;Eve&lt;/a&gt;
      &lt;/li&gt;
      &lt;li <span class="diff">typeof=&quot;foaf:Person&quot;</span>&gt;
        &lt;a <span class="diff">rel=&quot;foaf:homepage&quot; href=&quot;http://example.com/manu/&quot; property=&quot;foaf:name&quot; </span>&gt;Manu&lt;/a&gt;
      &lt;/li&gt;
   &lt;/ul&gt;
</ins>
&lt;/div&gt;
</pre>
<p>
An
example
JSON-LD
implementation
using
a
single
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
is
described
below.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@graph&quot;:
  [
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/bob/&quot;,
      &quot;foaf:name&quot;: &quot;Bob&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/eve/&quot;,
      &quot;foaf:name&quot;: &quot;Eve&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/manu/&quot;,
      &quot;foaf:name&quot;: &quot;Manu&quot;
    }
  ]
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@graph&quot;:
  [
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/bob/&quot;,
      &quot;foaf:name&quot;: &quot;Bob&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/eve/&quot;,
      &quot;foaf:name&quot;: &quot;Eve&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/manu/&quot;,
      &quot;foaf:name&quot;: &quot;Manu&quot;
    }
  ]
</ins>
}
</pre>
</div>
<div id="microformats" typeof="bibo:Chapter" resource="#microformats" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
<del class="diff-old">A.3
</del>
<ins class="diff-chg">B.3
</ins>
</span>
Microformats
</h3>
<p>
The
following
example
uses
a
simple
Microformats
hCard
example
to
express
how
the
Microformat
is
represented
in
JSON-LD.
</p>
<del class="diff-old">&lt;div class=&quot;vcard&quot;&gt;
 &lt;a class=&quot;url fn&quot; href=&quot;http://www.markus-lanthaler.com/&quot;&gt;Markus Lanthaler&lt;/a&gt;
</del>
<pre class="example">&lt;div class=&quot;vcard&quot;&gt;
<ins class="diff-chg"> &lt;a class=&quot;url fn&quot; href=&quot;http://tantek.com/&quot;&gt;Tantek Çelik&lt;/a&gt;
</ins>
&lt;/div&gt;
</pre>
<p>
The
representation
of
the
hCard
expresses
the
Microformat
terms
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
and
uses
them
directly
for
the
<code>
url
</code>
and
<code>
fn
</code>
properties.
Also
note
that
the
Microformat
to
JSON-LD
processor
has
generated
the
proper
URL
type
for
<code>
http://tantek.com/
</code>.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;vcard&quot;: &quot;http://microformats.org/profile/hcard#vcard&quot;,
    &quot;url&quot;:
    {
      &quot;@id&quot;: &quot;http://microformats.org/profile/hcard#url&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;fn&quot;: &quot;http://microformats.org/profile/hcard#fn&quot;
  },
  &quot;@type&quot;: &quot;vcard&quot;,
  &quot;url&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;fn&quot;: &quot;Markus Lanthaler&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;vcard&quot;: &quot;http://microformats.org/profile/hcard#vcard&quot;,
    &quot;url&quot;:
    {
      &quot;@id&quot;: &quot;http://microformats.org/profile/hcard#url&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;fn&quot;: &quot;http://microformats.org/profile/hcard#fn&quot;
  },
  &quot;@type&quot;: &quot;vcard&quot;,
  &quot;url&quot;: &quot;http://tantek.com/&quot;,
  &quot;fn&quot;: &quot;Tantek Çelik&quot;
</ins>
}
</pre>
</div>
<div id="microdata" typeof="bibo:Chapter" resource="#microdata" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
<del class="diff-old">A.4
</del>
<ins class="diff-chg">B.4
</ins>
</span>
Microdata
</h3>
<p>
The
microdata
example
below
expresses
book
information
as
a
microdata
Work
item.
</p>
<del class="diff-old">&lt;dl itemscope
    itemtype=&quot;http://purl.org/vocab/frbr/core#Work&quot;
    itemid=&quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;&gt;
 &lt;dt&gt;Title&lt;/dt&gt;
 &lt;dd&gt;&lt;cite itemprop=&quot;http://purl.org/dc/terms/title&quot;&gt;Just a Geek&lt;/cite&gt;&lt;/dd&gt;
 &lt;dt&gt;By&lt;/dt&gt;
 &lt;dd&gt;&lt;span itemprop=&quot;http://purl.org/dc/terms/creator&quot;&gt;Wil Wheaton&lt;/span&gt;&lt;/dd&gt;
 &lt;dt&gt;Format&lt;/dt&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/BOOK&quot;&gt;
  Print
 &lt;/dd&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/EBOOK&quot;&gt;
  Ebook
 &lt;/dd&gt;
</del>
<pre class="example">&lt;dl itemscope
<ins class="diff-chg">    itemtype=&quot;http://purl.org/vocab/frbr/core#Work&quot;
    itemid=&quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;&gt;
 &lt;dt&gt;Title&lt;/dt&gt;
 &lt;dd&gt;&lt;cite itemprop=&quot;http://purl.org/dc/terms/title&quot;&gt;Just a Geek&lt;/cite&gt;&lt;/dd&gt;
 &lt;dt&gt;By&lt;/dt&gt;
 &lt;dd&gt;&lt;span itemprop=&quot;http://purl.org/dc/terms/creator&quot;&gt;Wil Wheaton&lt;/span&gt;&lt;/dd&gt;
 &lt;dt&gt;Format&lt;/dt&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/BOOK&quot;&gt;
  Print
 &lt;/dd&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/EBOOK&quot;&gt;
  Ebook
 &lt;/dd&gt;
</ins>
&lt;/dl&gt;
</pre>
<p>
Note
that
the
JSON-LD
representation
of
the
Microdata
information
stays
true
to
the
desires
of
the
Microdata
community
to
avoid
contexts
and
instead
refer
to
items
by
their
full
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<del class="diff-old">[
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Work&quot;,
    &quot;http://purl.org/dc/terms/title&quot;: &quot;Just a Geek&quot;,
    &quot;http://purl.org/dc/terms/creator&quot;: &quot;Whil Wheaton&quot;,
    &quot;http://purl.org/vocab/frbr/core#realization&quot;:
    [
      &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
      &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;
    ]
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/BOOK&quot;
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/EBOOK&quot;
  }
</del>
<pre class="example">[
<ins class="diff-chg">  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Work&quot;,
    &quot;http://purl.org/dc/terms/title&quot;: &quot;Just a Geek&quot;,
    &quot;http://purl.org/dc/terms/creator&quot;: &quot;Whil Wheaton&quot;,
    &quot;http://purl.org/vocab/frbr/core#realization&quot;:
    [
      &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
      &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;
    ]
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/BOOK&quot;
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/EBOOK&quot;
  }
</ins>
]
</pre>
</div>
</div>
<del class="diff-old">B.
Linked
Data
The
following
definition
for
Linked
Data
is
the
one
that
will
be
used
for
this
specification.
Linked
Data
is
a
set
of
documents,
each
containing
a
representation
of
a
linked
data
graph.
A
linked
data
graph
is
an
unordered
labeled
directed
graph,
where
nodes
are
subject
s
or
object
s,
and
edges
are
properties.
A
subject
is
any
node
in
a
linked
data
graph
with
at
least
one
outgoing
edge.
A
subject
should
be
labeled
with
an
IRI
(an
Internationalized
Resource
Identifier
as
described
in
[
RFC3987
]).
An
object
is
a
node
in
a
linked
data
graph
with
at
least
one
incoming
edge.
An
object
may
be
labeled
with
an
IRI
.
A
node
may
be
a
subject
and
object
at
the
same
time.
A
property
is
an
edge
of
the
linked
data
graph
.
A
property
should
be
labeled
with
an
IRI
.
An
IRI
that
is
a
label
in
a
linked
data
graph
should
be
dereferencable
to
a
Linked
Data
document
describing
the
labeled
subject
,
object
or
property
.
A
value
is
an
object
with
a
label
that
is
not
an
IRI
Note
that
the
definition
for
Linked
Data
above
is
silent
on
the
topic
of
unlabeled
nodes.
Unlabeled
nodes
are
not
considered
Linked
Data
.
However,
this
specification
allows
for
the
expression
of
unlabled
nodes,
as
most
graph-based
data
sets
on
the
Web
contain
a
number
of
associated
nodes
that
are
not
named
and
thus
are
not
directly
de-referenceable.
</del>
<div class="appendix informative section" id="iana-considerations" typeof="bibo:Chapter" resource="#iana-considerations" rel="bibo:chapter">
<h2>
<span class="secno">
C.
</span>
<del class="diff-old">Mashing
Up
Vocabularies
This
section
is
non-normative.
Developers
benefit
by
being
able
to
mash
other
vocabularies
into
their
JSON-LD
markup.
There
are
over
200
vocabularies
that
are
available
for
use
on
the
Web
today.
Some
of
these
vocabularies
include:
RDF
-
for
describing
information
about
objects
and
concepts
on
the
Web.
RDFS
-
for
expressing
things
like
labels
and
comments.
XSD
-
for
specifying
basic
types
like
strings,
integers,
dates
and
times.
Dublin
Core
-
for
describing
creative
works.
FOAF
-
for
describing
social
networks.
Calendar
-
for
specifying
events.
SIOC
-
for
describing
discussions
on
blogs
and
websites.
CCrel
-
for
describing
Creative
Commons
and
other
types
of
licenses.
GEO
-
for
describing
geographic
location.
VCard
-
for
describing
organizations
and
people.
DOAP
-
for
describing
projects.
You
can
use
these
vocabularies
in
combination,
like
so:
{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;sioc&quot;: &quot;http://rdfs.org/sioc/ns#&quot;,
    &quot;rdfs&quot;: &quot;http://www.w3.org/2000/01/rdf-schema#&quot;
  },
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;sioc:avatar&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;,
  &quot;rdfs:comment&quot;: &quot;Likes puppies, unicorns and rainbows.&quot;
}
Developers
can
also
specify
their
own
vocabulary
documents
by
modifying
the
active
context
in-line
using
the
@context
keyword,
like
so:
{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;sioc&quot;: &quot;http://rdfs.org/sioc/ns#&quot;,
    &quot;rdfs&quot;: &quot;http://www.w3.org/2000/01/rdf-schema#&quot;,
    
  },
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;sioc:avatar&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;,
  &quot;rdfs:comment&quot;: &quot;Likes puppies, unicorns and rainbows.&quot;
  
}
D.
</del>
IANA
Considerations
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
This
section
is
included
merely
for
standards
community
review
and
will
be
submitted
to
the
Internet
Engineering
Steering
Group
if
this
specification
becomes
a
W3C
Recommendation.
</p>
<h3 id="application-ld-json">
<ins class="diff-new">application/ld+json
</ins></h3>
<dl>
<dt>
Type
name:
</dt>
<dd>
application
</dd>
<dt>
Subtype
name:
</dt>
<dd>
ld+json
</dd>
<dt>
Required
parameters:
</dt>
<dd>
None
</dd>
<dt>
Optional
parameters:
</dt>
<dd>
<dl>
<dt>
<code>
form
</code>
</dt>
<dd>
Determines
the
serialization
form
for
the
JSON-LD
document.
The
only
valid
value
at
the
moment
is
<code>
expanded
</code>.
If
no
form
is
specified
in
an
HTTP
request
header
to
an
HTTP
server,
the
server
<em class="rfc2119" title="may">
may
</em>
choose
any
form.
If
no
form
is
specified
in
an
HTTP
response,
the
form
<em class="rfc2119" title="must not">
must
not
</em>
be
assumed
to
take
any
particular
form.
</dd>
</dl>
</dd>
<dt>
Encoding
considerations:
</dt>
<dd>
The
same
as
the
<code>
application/json
</code>
MIME
media
type.
</dd>
<dt>
Security
considerations:
</dt>
<dd>
Since
JSON-LD
is
intended
to
be
a
pure
data
exchange
format
for
directed
graphs,
the
serialization
<em class="rfc2119" title="should not">
should
not
</em>
be
passed
through
a
code
execution
mechanism
such
as
JavaScript's
<code>
eval()
</code>
function.
It
is
<em class="rfc2119" title="recommended">
recommended
</em>
that
a
conforming
parser
does
not
attempt
to
directly
evaluate
the
JSON-LD
serialization
and
instead
purely
parse
the
input
into
a
language-native
data
structure.
</dd>
<dt>
Interoperability
considerations:
</dt>
<dd>
Not
Applicable
</dd>
<dt>
Published
specification:
</dt>
<dd>
The
<a href="http://json-ld.org/spec/latest/">
JSON-LD
</a>
specification.
</dd>
<dt>
Applications
that
use
this
media
type:
</dt>
<dd>
Any
programming
environment
that
requires
the
exchange
of
directed
graphs.
Implementations
of
JSON-LD
have
been
created
for
JavaScript,
Python,
Ruby,
PHP
and
C++.
</dd>
<dt>
Additional
information:
</dt>
<dd>
<dl>
<dt>
Magic
number(s):
</dt>
<dd>
Not
Applicable
</dd>
<dt>
File
extension(s):
</dt>
<dd>.jsonld
</dd>
<dt>
Macintosh
file
type
code(s):
</dt>
<dd>
TEXT
</dd>
</dl>
</dd>
<dt>
Person
&amp;
email
address
to
contact
for
further
information:
</dt>
<dd>
Manu
Sporny
&lt;msporny@digitalbazaar.com&gt;
</dd>
<dt>
Intended
usage:
</dt>
<dd>
Common
</dd>
<dt>
Restrictions
on
usage:
</dt>
<dd>
None
</dd>
<dt>
Author(s):
</dt>
<dd>
Manu
Sporny,
Gregg
Kellogg,
Markus
Lanthaler,
Dave
Longley
</dd>
<dt>
Change
controller:
</dt>
<dd>
W3C
</dd>
</dl>
<p>
<ins class="diff-new">Fragment
identifiers
used
with
</ins><a href="#application-ld-json"><ins class="diff-new">
application/ld+json
</ins></a><ins class="diff-new">
resources
</ins><em class="rfc2119" title="may"><ins class="diff-new">
may
</ins></em><ins class="diff-new">
identify
a
node
in
the
</ins><a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph"><ins class="diff-new">
linked
data
graph
</ins></a><ins class="diff-new">
expressed
in
the
resource.
This
idiom,
which
is
also
used
in
RDF
[
</ins><cite><a class="bibref" rel="biblioentry" href="#bib-RDF-CONCEPTS"><ins class="diff-new">
RDF-CONCEPTS
</ins></a></cite><ins class="diff-new">
],
gives
a
simple
way
to
&quot;mint&quot;
new,
document-local
IRIs
to
label
nodes
and
therefore
contributes
considerably
to
the
expressive
power
of
JSON-LD.
</ins></p>
</div>
<div class="appendix informative section" id="acknowledgements" typeof="bibo:Chapter" resource="#acknowledgements" rel="bibo:chapter">
<h2>
<span class="secno">
<del class="diff-old">E.
</del>
<ins class="diff-chg">D.
</ins>
</span>
Acknowledgements
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
The
editors
would
like
to
thank
Mark
Birbeck,
who
provided
a
great
deal
of
the
initial
push
behind
the
JSON-LD
work
via
his
work
on
RDFj,
Dave
Longley,
Dave
Lehn
and
Mike
Johnson
who
reviewed,
provided
feedback,
and
performed
several
implementations
of
the
specification,
and
Ian
Davis,
who
created
RDF/JSON.
Thanks
also
to
Nathan
Rixham,
Bradley
P.
Allen,
Kingsley
Idehen,
Glenn
McDonald,
Alexandre
Passant,
Danny
Ayers,
Ted
Thibodeau
Jr.,
Olivier
Grisel,
Niklas
Lindström,
Markus
Lanthaler,
and
Richard
Cyganiak
for
their
input
on
the
specification.
</p>
</div>
<div id="references" class="appendix section" typeof="bibo:Chapter" resource="#references" rel="bibo:chapter">
<h2>
<span class="secno">
<del class="diff-old">F.
</del>
<ins class="diff-chg">E.
</ins>
</span>
References
</h2>
<div id="normative-references" typeof="bibo:Chapter" resource="#normative-references" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
<del class="diff-old">F.1
</del>
<ins class="diff-chg">E.1
</ins>
</span>
Normative
references
</h3>
<dl class="bibliography" about="">
<dt id="bib-BCP47">
[BCP47]
</dt>
<dd rel="dcterms:requires">
A.
Phillips,
M.
Davis.
<a href="http://tools.ietf.org/rfc/bcp/bcp47.txt">
<cite>
Tags
for
Identifying
Languages
</cite>
</a>
September
2009.
IETF
Best
Current
Practice.
URL:
<a href="http://tools.ietf.org/rfc/bcp/bcp47.txt">
http://tools.ietf.org/rfc/bcp/bcp47.txt
</a>
</dd>
<del class="diff-old">[JSON-LD-API]
Manu
Sporny,
Gregg
Kellogg,
Dave
Longley,
Markus
Lanthaler,
Eds.
JSON-LD
API
Latest.
W3C
Editor's
Draft.
URL:
http://json-ld.org/spec/latest/json-ld-api/
</del>
<dt id="bib-RFC3987">
[RFC3987]
</dt>
<dd rel="dcterms:requires">
M.
Dürst;
M.
Suignard.
<a href="http://www.ietf.org/rfc/rfc3987.txt">
<cite>
Internationalized
Resource
Identifiers
(IRIs).
</cite>
</a>
January
2005.
Internet
RFC
3987.
URL:
<a href="http://www.ietf.org/rfc/rfc3987.txt">
http://www.ietf.org/rfc/rfc3987.txt
</a>
</dd>
<dt id="bib-RFC4627">
[RFC4627]
</dt>
<dd rel="dcterms:requires">
D.
Crockford.
<a href="http://www.ietf.org/rfc/rfc4627.txt">
<cite>
The
application/json
Media
Type
for
JavaScript
Object
Notation
(JSON)
</cite>
</a>
July
2006.
Internet
RFC
4627.
URL:
<a href="http://www.ietf.org/rfc/rfc4627.txt">
http://www.ietf.org/rfc/rfc4627.txt
</a>
</dd>
<dt id="bib-RFC5988">
[RFC5988]
</dt>
<dd rel="dcterms:requires">
M.
Nottingham.
<a href="http://tools.ietf.org/rfc/rfc5988">
<cite>
Web
Linking
</cite>
</a>
October
2010.
IETF
Standard.
URL:
<a href="http://tools.ietf.org/rfc/rfc5988.txt">
http://tools.ietf.org/rfc/rfc5988.txt
</a>
</dd>
<del class="diff-old">[WEBIDL]
Cameron
McCormack.
Web
IDL.
27
September
2011.
W3C
Working
Draft.
(Work
in
progress.)
URL:
http://www.w3.org/TR/2011/WD-WebIDL-20110927/
</del>
</dl>
</div>
<div id="informative-references" typeof="bibo:Chapter" resource="#informative-references" rel="bibo:chapter" class="section">
<h3>
<span class="secno">
<del class="diff-old">F.2
</del>
<ins class="diff-chg">E.2
</ins>
</span>
Informative
references
</h3>
<dl class="bibliography" about="">
<del class="diff-old">[ECMA-262]
</del>
<dt id="bib-JSON-LD-API">
<ins class="diff-chg">[JSON-LD-API]
</ins>
</dt>
<dd rel="dcterms:references">
<ins class="diff-chg">Manu
Sporny,
Gregg
Kellogg,
Dave
Longley,
Markus
Lanthaler,
Eds.
</ins>
<cite>
<del class="diff-old">ECMAScript
Language
Specification.
</del>
<a href="http://json-ld.org/spec/latest/json-ld-api/">
<ins class="diff-new">JSON-LD
API
</ins>
</a>
<del class="diff-old">December
1999.
</del>
</cite>
<ins class="diff-chg">Latest.
W3C
Editor's
Draft.
</ins>
URL:
<del class="diff-old">http://www.ecma-international.org/publications/standards/Ecma-262.htm
</del>
<a href="http://json-ld.org/spec/latest/json-ld-api/">
<ins class="diff-chg">http://json-ld.org/spec/latest/json-ld-api/
</ins>
</a>
</dd>
<del class="diff-old">[HTML-RDFA]
</del>
<dt id="bib-RDF-CONCEPTS">
<ins class="diff-chg">[RDF-CONCEPTS]
</ins>
</dt>
<del class="diff-old">Manu
Sporny;
et
al.
</del>
<dd rel="dcterms:references">
<ins class="diff-chg">Graham
Klyne;
Jeremy
J.
Carroll.
</ins><a href="http://www.w3.org/TR/2004/REC-rdf-concepts-20040210">
<cite>
<del class="diff-old">HTML+RDFa
</del>
<ins class="diff-chg">Resource
Description
Framework
(RDF):
Concepts
and
Abstract
Syntax.
</ins>
</cite>
</a>
<del class="diff-old">04
March
2010.
</del>
<ins class="diff-chg">10
February
2004.
</ins>
W3C
<del class="diff-old">Working
Draft.
</del>
<ins class="diff-chg">Recommendation.
</ins>
URL:
<del class="diff-old">http://www.w3.org/TR/rdfa-in-html/
</del>
<a href="http://www.w3.org/TR/2004/REC-rdf-concepts-20040210">
<ins class="diff-chg">http://www.w3.org/TR/2004/REC-rdf-concepts-20040210
</ins>
</a>
</dd>
<dt id="bib-RDF-PRIMER">
[RDF-PRIMER]
</dt>
<dd rel="dcterms:references">
Frank
Manola;
Eric
Miller.
<a href="http://www.w3.org/TR/2004/REC-rdf-primer-20040210/">
<cite>
RDF
Primer.
</cite>
</a>
10
February
2004.
W3C
Recommendation.
URL:
<a href="http://www.w3.org/TR/2004/REC-rdf-primer-20040210/">
http://www.w3.org/TR/2004/REC-rdf-primer-20040210/
</a>
</dd>
<dt id="bib-RDFA-CORE">
[RDFA-CORE]
</dt>
<dd rel="dcterms:references">
Shane
McCarron;
et
al.
<a href="http://www.w3.org/TR/2012/PR-rdfa-core-20120508/">
<cite>
RDFa
Core
1.1:
Syntax
and
processing
rules
for
embedding
RDF
through
attributes.
</cite>
</a>
<del class="diff-old">13
March
</del>
<ins class="diff-chg">8
May
</ins>
2012.
W3C
<del class="diff-old">Candidate
</del>
<ins class="diff-chg">Proposed
</ins>
Recommendation.
URL:
<del class="diff-old">http://www.w3.org/TR/2012/CR-rdfa-core-20120313/
</del>
<a href="http://www.w3.org/TR/2012/PR-rdfa-core-20120508/">
<ins class="diff-chg">http://www.w3.org/TR/2012/PR-rdfa-core-20120508/
</ins>
</a>
</dd>
<dt id="bib-TURTLE">
[TURTLE]
</dt>
<dd rel="dcterms:references">
David
Beckett,
Tim
Berners-Lee.
<a href="http://www.w3.org/TeamSubmission/turtle/">
<cite>
Turtle:
Terse
RDF
Triple
Language.
</cite>
</a>
January
2008.
W3C
Team
Submission.
URL:
<a href="http://www.w3.org/TeamSubmission/turtle/">
http://www.w3.org/TeamSubmission/turtle/
</a>
</dd>
</dl>
</div>
</div>
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